chrome/browser/about_flags.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/about_flags.h"
   6
   7 #include <algorithm>
   8 #include <iterator>
   9 #include <map>
  10 #include <set>
  11 #include <utility>
  12
  13 #include "base/command_line.h"
  14 #include "base/memory/singleton.h"
  15 #include "base/prefs/pref_service.h"
  16 #include "base/strings/string_number_conversions.h"
  17 #include "base/utf_string_conversions.h"
  18 #include "base/values.h"
  19 #include "cc/base/switches.h"
  20 #include "chrome/browser/prefs/scoped_user_pref_update.h"
  21 #include "chrome/common/chrome_content_client.h"
  22 #include "chrome/common/chrome_switches.h"
  23 #include "chrome/common/pref_names.h"
  24 #include "content/public/browser/user_metrics.h"
  25 #include "grit/chromium_strings.h"
  26 #include "grit/generated_resources.h"
  27 #include "grit/google_chrome_strings.h"
  28 #include "media/base/media_switches.h"
  29 #include "ui/app_list/app_list_switches.h"
  30 #include "ui/base/l10n/l10n_util.h"
  31 #include "ui/base/ui_base_switches.h"
  32 #include "ui/gfx/switches.h"
  33 #include "ui/gl/gl_switches.h"
  34 #include "ui/keyboard/keyboard_switches.h"
  35 #include "ui/surface/surface_switches.h"
  36
  37 #if defined(ENABLE_MESSAGE_CENTER)
  38 #include "ui/message_center/message_center_switches.h"
  39 #endif
  40
  41 #if defined(USE_ASH)
  42 #include "ash/ash_switches.h"
  43 #endif
  44
  45 #if defined(OS_CHROMEOS)
  46 #include "chromeos/chromeos_switches.h"
  47 #endif
  48
  49 using content::UserMetricsAction;
  50
  51 namespace about_flags {
  52
  53 // Macros to simplify specifying the type.
  54 #define SINGLE_VALUE_TYPE_AND_VALUE(command_line_switch, switch_value) \
  55     Experiment::SINGLE_VALUE, \
  56     command_line_switch, switch_value, NULL, NULL, NULL, 0
  57 #define SINGLE_VALUE_TYPE(command_line_switch) \
  58     SINGLE_VALUE_TYPE_AND_VALUE(command_line_switch, "")
  59 #define ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(enable_switch, enable_value, \
  60                                             disable_switch, disable_value) \
  61     Experiment::ENABLE_DISABLE_VALUE, enable_switch, enable_value, \
  62     disable_switch, disable_value, NULL, 3
  63 #define ENABLE_DISABLE_VALUE_TYPE(enable_switch, disable_switch) \
  64     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(enable_switch, "", disable_switch, "")
  65 #define MULTI_VALUE_TYPE(choices) \
  66     Experiment::MULTI_VALUE, NULL, NULL, NULL, NULL, choices, arraysize(choices)
  67
  68 namespace {
  69
  70 const unsigned kOsAll = kOsMac | kOsWin | kOsLinux | kOsCrOS | kOsAndroid;
  71 const unsigned kOsDesktop = kOsMac | kOsWin | kOsLinux | kOsCrOS;
  72
  73 // Adds a |StringValue| to |list| for each platform where |bitmask| indicates
  74 // whether the experiment is available on that platform.
  75 void AddOsStrings(unsigned bitmask, ListValue* list) {
  76   struct {
  77     unsigned bit;
  78     const char* const name;
  79   } kBitsToOs[] = {
  80     {kOsMac, "Mac"},
  81     {kOsWin, "Windows"},
  82     {kOsLinux, "Linux"},
  83     {kOsCrOS, "Chrome OS"},
  84     {kOsAndroid, "Android"},
  85     {kOsCrOSOwnerOnly, "Chrome OS (owner only)"},
  86   };
  87   for (size_t i = 0; i < ARRAYSIZE_UNSAFE(kBitsToOs); ++i)
  88     if (bitmask & kBitsToOs[i].bit)
  89       list->Append(new StringValue(kBitsToOs[i].name));
  90 }
  91
  92 const Experiment::Choice
  93     kOmniboxHistoryQuickProviderReorderForInliningChoices[] = {
  94   { IDS_FLAGS_OMNIBOX_HISTORY_QUICK_PROVIDER_REORDER_FOR_INLINING_AUTOMATIC,
  95     "",
  96     "" },
  97   { IDS_FLAGS_OMNIBOX_HISTORY_QUICK_PROVIDER_REORDER_FOR_INLINING_ENABLED,
  98     switches::kOmniboxHistoryQuickProviderReorderForInlining,
  99     switches::kOmniboxHistoryQuickProviderReorderForInliningEnabled },
 100   { IDS_FLAGS_OMNIBOX_HISTORY_QUICK_PROVIDER_REORDER_FOR_INLINING_DISABLED,
 101     switches::kOmniboxHistoryQuickProviderReorderForInlining,
 102     switches::kOmniboxHistoryQuickProviderReorderForInliningDisabled }
 103 };
 104
 105 const Experiment::Choice kOmniboxInlineHistoryQuickProviderChoices[] = {
 106   { IDS_FLAGS_OMNIBOX_INLINE_HISTORY_QUICK_PROVIDER_AUTOMATIC, "", "" },
 107   { IDS_FLAGS_OMNIBOX_INLINE_HISTORY_QUICK_PROVIDER_ALLOWED,
 108     switches::kOmniboxInlineHistoryQuickProvider,
 109     switches::kOmniboxInlineHistoryQuickProviderAllowed },
 110   { IDS_FLAGS_OMNIBOX_INLINE_HISTORY_QUICK_PROVIDER_PROHIBITED,
 111     switches::kOmniboxInlineHistoryQuickProvider,
 112     switches::kOmniboxInlineHistoryQuickProviderProhibited }
 113 };
 114
 115 const Experiment::Choice kEnableCompositingForFixedPositionChoices[] = {
 116   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 117   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
 118     switches::kEnableCompositingForFixedPosition, ""},
 119   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 120     switches::kDisableCompositingForFixedPosition, ""},
 121   { IDS_FLAGS_COMPOSITING_FOR_FIXED_POSITION_HIGH_DPI,
 122     switches::kEnableHighDpiCompositingForFixedPosition, ""}
 123 };
 124
 125 const Experiment::Choice kGDIPresentChoices[] = {
 126   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 127   { IDS_FLAGS_PRESENT_WITH_GDI_FIRST_SHOW,
 128     switches::kDoFirstShowPresentWithGDI, ""},
 129   { IDS_FLAGS_PRESENT_WITH_GDI_ALL_SHOW,
 130     switches::kDoAllShowPresentWithGDI, ""}
 131 };
 132
 133 const Experiment::Choice kTouchEventsChoices[] = {
 134   { IDS_GENERIC_EXPERIMENT_CHOICE_AUTOMATIC, "", "" },
 135   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
 136     switches::kTouchEvents,
 137     switches::kTouchEventsEnabled },
 138   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 139     switches::kTouchEvents,
 140     switches::kTouchEventsDisabled }
 141 };
 142
 143 const Experiment::Choice kTouchOptimizedUIChoices[] = {
 144   { IDS_GENERIC_EXPERIMENT_CHOICE_AUTOMATIC, "", "" },
 145   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
 146     switches::kTouchOptimizedUI,
 147     switches::kTouchOptimizedUIEnabled },
 148   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 149     switches::kTouchOptimizedUI,
 150     switches::kTouchOptimizedUIDisabled }
 151 };
 152
 153 const Experiment::Choice kNaClDebugMaskChoices[] = {
 154   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 155   // Secure shell can be used on ChromeOS for forwarding the TCP port opened by
 156   // debug stub to a remote machine. Since secure shell uses NaCl, we provide
 157   // an option to switch off its debugging.
 158   { IDS_NACL_DEBUG_MASK_CHOICE_EXCLUDE_UTILS,
 159       switches::kNaClDebugMask, "!*://*/*ssh_client.nmf" },
 160   { IDS_NACL_DEBUG_MASK_CHOICE_INCLUDE_DEBUG,
 161       switches::kNaClDebugMask, "*://*/*debug.nmf" }
 162 };
 163
 164 #if defined(OS_CHROMEOS)
 165 const Experiment::Choice kAshBootAnimationFunction[] = {
 166   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 167   { IDS_FLAGS_ASH_BOOT_ANIMATION_FUNCTION2,
 168     ash::switches::kAshBootAnimationFunction2, ""},
 169   { IDS_FLAGS_ASH_BOOT_ANIMATION_FUNCTION3,
 170     ash::switches::kAshBootAnimationFunction3, ""}
 171 };
 172
 173 const Experiment::Choice kChromeCaptivePortalDetectionChoices[] = {
 174   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 175   { IDS_FLAGS_CHROME_CAPTIVE_PORTAL_DETECTOR,
 176     chromeos::switches::kEnableChromeCaptivePortalDetector, "" },
 177   { IDS_FLAGS_SHILL_CAPTIVE_PORTAL_DETECTOR,
 178     chromeos::switches::kDisableChromeCaptivePortalDetector, "" }
 179 };
 180
 181 #endif
 182
 183 const Experiment::Choice kImplSidePaintingChoices[] = {
 184   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 185   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
 186     cc::switches::kEnableImplSidePainting, ""},
 187   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 188     cc::switches::kDisableImplSidePainting, ""}
 189 };
 190
 191 const Experiment::Choice kMaxTilesForInterestAreaChoices[] = {
 192   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 193   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_SHORT,
 194     cc::switches::kMaxTilesForInterestArea, "64"},
 195   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_TALL,
 196     cc::switches::kMaxTilesForInterestArea, "128"},
 197   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_GRANDE,
 198     cc::switches::kMaxTilesForInterestArea, "256"},
 199   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_VENTI,
 200     cc::switches::kMaxTilesForInterestArea, "512"}
 201 };
 202
 203 const Experiment::Choice kDefaultTileWidthChoices[] = {
 204   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 205   { IDS_FLAGS_DEFAULT_TILE_WIDTH_SHORT,
 206     switches::kDefaultTileWidth, "128"},
 207   { IDS_FLAGS_DEFAULT_TILE_WIDTH_TALL,
 208     switches::kDefaultTileWidth, "256"},
 209   { IDS_FLAGS_DEFAULT_TILE_WIDTH_GRANDE,
 210     switches::kDefaultTileWidth, "512"},
 211   { IDS_FLAGS_DEFAULT_TILE_WIDTH_VENTI,
 212     switches::kDefaultTileWidth, "1024"}
 213 };
 214
 215 const Experiment::Choice kDefaultTileHeightChoices[] = {
 216   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 217   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_SHORT,
 218     switches::kDefaultTileHeight, "128"},
 219   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_TALL,
 220     switches::kDefaultTileHeight, "256"},
 221   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_GRANDE,
 222     switches::kDefaultTileHeight, "512"},
 223   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_VENTI,
 224     switches::kDefaultTileHeight, "1024"}
 225 };
 226
 227 const Experiment::Choice kSimpleCacheBackendChoices[] = {
 228   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 229   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 230     switches::kUseSimpleCacheBackend, "off" },
 231   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
 232     switches::kUseSimpleCacheBackend, "on"}
 233 };
 234
 235 // RECORDING USER METRICS FOR FLAGS:
 236 // -----------------------------------------------------------------------------
 237 // The first line of the experiment is the internal name. If you'd like to
 238 // gather statistics about the usage of your flag, you should append a marker
 239 // comment to the end of the feature name, like so:
 240 //   "my-special-feature",  // FLAGS:RECORD_UMA
 241 //
 242 // After doing that, run //chrome/tools/extract_actions.py (see instructions at
 243 // the top of that file for details) to update the chromeactions.txt file, which
 244 // will enable UMA to record your feature flag.
 245 //
 246 // After your feature has shipped under a flag, you can locate the metrics under
 247 // the action name AboutFlags_internal-action-name. Actions are recorded once
 248 // per startup, so you should divide this number by AboutFlags_StartupTick to
 249 // get a sense of usage. Note that this will not be the same as number of users
 250 // with a given feature enabled because users can quit and relaunch the
 251 // application multiple times over a given time interval. The dashboard also
 252 // shows you how many (metrics reporting) users have enabled the flag over the
 253 // last seven days. However, note that this is not the same as the number of
 254 // users who have the flag enabled, since enabling the flag happens once,
 255 // whereas running with the flag enabled happens until the user flips the flag
 256 // again.
 257
 258 // To add a new experiment add to the end of kExperiments. There are two
 259 // distinct types of experiments:
 260 // . SINGLE_VALUE: experiment is either on or off. Use the SINGLE_VALUE_TYPE
 261 //   macro for this type supplying the command line to the macro.
 262 // . MULTI_VALUE: a list of choices, the first of which should correspond to a
 263 //   deactivated state for this lab (i.e. no command line option).  To specify
 264 //   this type of experiment use the macro MULTI_VALUE_TYPE supplying it the
 265 //   array of choices.
 266 // See the documentation of Experiment for details on the fields.
 267 //
 268 // When adding a new choice, add it to the end of the list.
 269 const Experiment kExperiments[] = {
 270   {
 271     "expose-for-tabs",  // FLAGS:RECORD_UMA
 272     IDS_FLAGS_TABPOSE_NAME,
 273     IDS_FLAGS_TABPOSE_DESCRIPTION,
 274     kOsMac,
 275 #if defined(OS_MACOSX)
 276     // The switch exists only on OS X.
 277     SINGLE_VALUE_TYPE(switches::kEnableExposeForTabs)
 278 #else
 279     SINGLE_VALUE_TYPE("")
 280 #endif
 281   },
 282   {
 283     "conflicting-modules-check",  // FLAGS:RECORD_UMA
 284     IDS_FLAGS_CONFLICTS_CHECK_NAME,
 285     IDS_FLAGS_CONFLICTS_CHECK_DESCRIPTION,
 286     kOsWin,
 287     SINGLE_VALUE_TYPE(switches::kConflictingModulesCheck)
 288   },
 289   {
 290     "cloud-print-proxy",  // FLAGS:RECORD_UMA
 291     IDS_FLAGS_CLOUD_PRINT_CONNECTOR_NAME,
 292     IDS_FLAGS_CLOUD_PRINT_CONNECTOR_DESCRIPTION,
 293     // For a Chrome build, we know we have a PDF plug-in on Windows, so it's
 294     // fully enabled.
 295     // Otherwise, where we know Windows could be working if a viable PDF
 296     // plug-in could be supplied, we'll keep the lab enabled. Mac and Linux
 297     // always have PDF rasterization available, so no flag needed there.
 298 #if !defined(GOOGLE_CHROME_BUILD)
 299     kOsWin,
 300 #else
 301     0,
 302 #endif
 303     SINGLE_VALUE_TYPE(switches::kEnableCloudPrintProxy)
 304   },
 305 #if defined(OS_WIN)
 306   {
 307     "print-raster",
 308     IDS_FLAGS_PRINT_RASTER_NAME,
 309     IDS_FLAGS_PRINT_RASTER_DESCRIPTION,
 310     kOsWin,
 311     SINGLE_VALUE_TYPE(switches::kPrintRaster)
 312   },
 313 #endif  // OS_WIN
 314   {
 315     "ignore-gpu-blacklist",
 316     IDS_FLAGS_IGNORE_GPU_BLACKLIST_NAME,
 317     IDS_FLAGS_IGNORE_GPU_BLACKLIST_DESCRIPTION,
 318     kOsAll,
 319     SINGLE_VALUE_TYPE(switches::kIgnoreGpuBlacklist)
 320   },
 321   {
 322     "force-compositing-mode-2",
 323     IDS_FLAGS_FORCE_COMPOSITING_MODE_NAME,
 324     IDS_FLAGS_FORCE_COMPOSITING_MODE_DESCRIPTION,
 325     kOsMac | kOsWin | kOsLinux,
 326     ENABLE_DISABLE_VALUE_TYPE(switches::kForceCompositingMode,
 327                               switches::kDisableForceCompositingMode)
 328   },
 329   {
 330     "threaded-compositing-mode",
 331     IDS_FLAGS_THREADED_COMPOSITING_MODE_NAME,
 332     IDS_FLAGS_THREADED_COMPOSITING_MODE_DESCRIPTION,
 333     kOsMac | kOsWin | kOsLinux,
 334     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableThreadedCompositing,
 335                               switches::kDisableThreadedCompositing)
 336   },
 337   {
 338     "force-accelerated-composited-scrolling",
 339      IDS_FLAGS_FORCE_ACCELERATED_OVERFLOW_SCROLL_MODE_NAME,
 340      IDS_FLAGS_FORCE_ACCELERATED_OVERFLOW_SCROLL_MODE_DESCRIPTION,
 341      kOsAll,
 342      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAcceleratedOverflowScroll,
 343                                switches::kDisableAcceleratedOverflowScroll)
 344   },
 345   {
 346     "present-with-GDI",
 347     IDS_FLAGS_PRESENT_WITH_GDI_NAME,
 348     IDS_FLAGS_PRESENT_WITH_GDI_DESCRIPTION,
 349     kOsWin,
 350     MULTI_VALUE_TYPE(kGDIPresentChoices)
 351   },
 352   {
 353     "enable-experimental-canvas-features",
 354     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_NAME,
 355     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_DESCRIPTION,
 356     kOsAll,
 357     SINGLE_VALUE_TYPE(switches::kEnableExperimentalCanvasFeatures)
 358   },
 359   {
 360     "disable-accelerated-2d-canvas",
 361     IDS_FLAGS_DISABLE_ACCELERATED_2D_CANVAS_NAME,
 362     IDS_FLAGS_DISABLE_ACCELERATED_2D_CANVAS_DESCRIPTION,
 363     kOsAll,
 364     SINGLE_VALUE_TYPE(switches::kDisableAccelerated2dCanvas)
 365   },
 366   {
 367     "disable-threaded-animation",
 368     IDS_FLAGS_DISABLE_THREADED_ANIMATION_NAME,
 369     IDS_FLAGS_DISABLE_THREADED_ANIMATION_DESCRIPTION,
 370     kOsAll,
 371     SINGLE_VALUE_TYPE(cc::switches::kDisableThreadedAnimation)
 372   },
 373   {
 374     "composited-layer-borders",
 375     IDS_FLAGS_COMPOSITED_LAYER_BORDERS,
 376     IDS_FLAGS_COMPOSITED_LAYER_BORDERS_DESCRIPTION,
 377     kOsAll,
 378     SINGLE_VALUE_TYPE(cc::switches::kShowCompositedLayerBorders)
 379   },
 380   {
 381     "show-fps-counter",
 382     IDS_FLAGS_SHOW_FPS_COUNTER,
 383     IDS_FLAGS_SHOW_FPS_COUNTER_DESCRIPTION,
 384     kOsAll,
 385     SINGLE_VALUE_TYPE(cc::switches::kShowFPSCounter)
 386   },
 387   {
 388     "accelerated-filters",
 389     IDS_FLAGS_ACCELERATED_FILTERS,
 390     IDS_FLAGS_ACCELERATED_FILTERS_DESCRIPTION,
 391     kOsAll,
 392     SINGLE_VALUE_TYPE(switches::kEnableAcceleratedFilters)
 393   },
 394   {
 395     "disable-gpu-vsync",
 396     IDS_FLAGS_DISABLE_GPU_VSYNC_NAME,
 397     IDS_FLAGS_DISABLE_GPU_VSYNC_DESCRIPTION,
 398     kOsDesktop,
 399     SINGLE_VALUE_TYPE(switches::kDisableGpuVsync)
 400   },
 401   {
 402     "enable-webgl",
 403     IDS_FLAGS_ENABLE_WEBGL_NAME,
 404     IDS_FLAGS_ENABLE_WEBGL_DESCRIPTION,
 405     kOsAndroid,
 406 #if defined(OS_ANDROID)
 407     SINGLE_VALUE_TYPE(switches::kEnableExperimentalWebGL)
 408 #else
 409     SINGLE_VALUE_TYPE("")
 410 #endif
 411   },
 412   {
 413     "disable-webgl",
 414     IDS_FLAGS_DISABLE_WEBGL_NAME,
 415     IDS_FLAGS_DISABLE_WEBGL_DESCRIPTION,
 416     kOsDesktop,
 417 #if defined(OS_ANDROID)
 418     SINGLE_VALUE_TYPE("")
 419 #else
 420     SINGLE_VALUE_TYPE(switches::kDisableExperimentalWebGL)
 421 #endif
 422   },
 423   {
 424     "disable-webrtc",
 425     IDS_FLAGS_DISABLE_WEBRTC_NAME,
 426     IDS_FLAGS_DISABLE_WEBRTC_DESCRIPTION,
 427     kOsAndroid,
 428 #if defined(OS_ANDROID)
 429     SINGLE_VALUE_TYPE(switches::kDisableWebRTC)
 430 #else
 431     SINGLE_VALUE_TYPE("")
 432 #endif
 433   },
 434 #if defined(OS_ANDROID)
 435   {
 436     "enable-webaudio",
 437     IDS_FLAGS_ENABLE_WEBAUDIO_NAME,
 438     IDS_FLAGS_ENABLE_WEBAUDIO_DESCRIPTION,
 439     kOsAndroid,
 440     SINGLE_VALUE_TYPE(switches::kEnableWebAudio)
 441   },
 442 #endif
 443   {
 444     "fixed-position-creates-stacking-context",
 445     IDS_FLAGS_FIXED_POSITION_CREATES_STACKING_CONTEXT_NAME,
 446     IDS_FLAGS_FIXED_POSITION_CREATES_STACKING_CONTEXT_DESCRIPTION,
 447     kOsAll,
 448     ENABLE_DISABLE_VALUE_TYPE(
 449         switches::kEnableFixedPositionCreatesStackingContext,
 450         switches::kDisableFixedPositionCreatesStackingContext)
 451   },
 452   {
 453     "enable-compositing-for-fixed-position",
 454     IDS_FLAGS_COMPOSITING_FOR_FIXED_POSITION_NAME,
 455     IDS_FLAGS_COMPOSITING_FOR_FIXED_POSITION_DESCRIPTION,
 456     kOsAll,
 457     MULTI_VALUE_TYPE(kEnableCompositingForFixedPositionChoices)
 458   },
 459   // TODO(bbudge): When NaCl is on by default, remove this flag entry.
 460   {
 461     "enable-nacl",  // FLAGS:RECORD_UMA
 462     IDS_FLAGS_ENABLE_NACL_NAME,
 463     IDS_FLAGS_ENABLE_NACL_DESCRIPTION,
 464     kOsDesktop,
 465     SINGLE_VALUE_TYPE(switches::kEnableNaCl)
 466   },
 467   {
 468     "enable-nacl-debug",  // FLAGS:RECORD_UMA
 469     IDS_FLAGS_ENABLE_NACL_DEBUG_NAME,
 470     IDS_FLAGS_ENABLE_NACL_DEBUG_DESCRIPTION,
 471     kOsDesktop,
 472     SINGLE_VALUE_TYPE(switches::kEnableNaClDebug)
 473   },
 474   {
 475     "nacl-debug-mask",  // FLAGS:RECORD_UMA
 476     IDS_FLAGS_NACL_DEBUG_MASK_NAME,
 477     IDS_FLAGS_NACL_DEBUG_MASK_DESCRIPTION,
 478     kOsDesktop,
 479     MULTI_VALUE_TYPE(kNaClDebugMaskChoices)
 480   },
 481   {
 482     "enable-pnacl",  // FLAGS:RECORD_UMA
 483     IDS_FLAGS_ENABLE_PNACL_NAME,
 484     IDS_FLAGS_ENABLE_PNACL_DESCRIPTION,
 485     kOsDesktop,
 486     SINGLE_VALUE_TYPE(switches::kEnablePnacl)
 487   },
 488   {
 489     "extension-apis",  // FLAGS:RECORD_UMA
 490     IDS_FLAGS_EXPERIMENTAL_EXTENSION_APIS_NAME,
 491     IDS_FLAGS_EXPERIMENTAL_EXTENSION_APIS_DESCRIPTION,
 492     kOsDesktop,
 493     SINGLE_VALUE_TYPE(switches::kEnableExperimentalExtensionApis)
 494   },
 495   {
 496     "extensions-on-chrome-urls",
 497     IDS_FLAGS_EXTENSIONS_ON_CHROME_URLS_NAME,
 498     IDS_FLAGS_EXTENSIONS_ON_CHROME_URLS_DESCRIPTION,
 499     kOsAll,
 500     SINGLE_VALUE_TYPE(switches::kExtensionsOnChromeURLs)
 501   },
 502   {
 503     "enable-adview",
 504     IDS_FLAGS_ENABLE_ADVIEW_NAME,
 505     IDS_FLAGS_ENABLE_ADVIEW_DESCRIPTION,
 506     kOsDesktop,
 507     SINGLE_VALUE_TYPE(switches::kEnableAdview)
 508   },
 509   {
 510     "enable-adview-src-attribute",
 511     IDS_FLAGS_ENABLE_ADVIEW_SRC_ATTRIBUTE_NAME,
 512     IDS_FLAGS_ENABLE_ADVIEW_SRC_ATTRIBUTE_DESCRIPTION,
 513     kOsDesktop,
 514     SINGLE_VALUE_TYPE(switches::kEnableAdviewSrcAttribute)
 515   },
 516   {
 517     "action-box",
 518     IDS_FLAGS_ACTION_BOX_NAME,
 519     IDS_FLAGS_ACTION_BOX_DESCRIPTION,
 520     kOsDesktop,
 521     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(switches::kActionBox, "1",
 522                                         switches::kActionBox, "0")
 523   },
 524   {
 525     "script-badges",
 526     IDS_FLAGS_SCRIPT_BADGES_NAME,
 527     IDS_FLAGS_SCRIPT_BADGES_DESCRIPTION,
 528     kOsDesktop,
 529     SINGLE_VALUE_TYPE(switches::kScriptBadges)
 530   },
 531   {
 532     "script-bubble",
 533     IDS_FLAGS_SCRIPT_BUBBLE_NAME,
 534     IDS_FLAGS_SCRIPT_BUBBLE_DESCRIPTION,
 535     kOsDesktop,
 536     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(switches::kScriptBubble, "1",
 537                                         switches::kScriptBubble, "0")
 538   },
 539   {
 540     "apps-new-install-bubble",
 541     IDS_FLAGS_APPS_NEW_INSTALL_BUBBLE_NAME,
 542     IDS_FLAGS_APPS_NEW_INSTALL_BUBBLE_DESCRIPTION,
 543     kOsDesktop,
 544     SINGLE_VALUE_TYPE(switches::kAppsNewInstallBubble)
 545   },
 546   {
 547     "disable-hyperlink-auditing",
 548     IDS_FLAGS_DISABLE_HYPERLINK_AUDITING_NAME,
 549     IDS_FLAGS_DISABLE_HYPERLINK_AUDITING_DESCRIPTION,
 550     kOsAll,
 551     SINGLE_VALUE_TYPE(switches::kNoPings)
 552   },
 553   {
 554     "experimental-location-features",  // FLAGS:RECORD_UMA
 555     IDS_FLAGS_EXPERIMENTAL_LOCATION_FEATURES_NAME,
 556     IDS_FLAGS_EXPERIMENTAL_LOCATION_FEATURES_DESCRIPTION,
 557     kOsMac | kOsWin | kOsLinux,  // Currently does nothing on CrOS.
 558     SINGLE_VALUE_TYPE(switches::kExperimentalLocationFeatures)
 559   },
 560   {
 561     "tab-groups-context-menu",
 562     IDS_FLAGS_TAB_GROUPS_CONTEXT_MENU_NAME,
 563     IDS_FLAGS_TAB_GROUPS_CONTEXT_MENU_DESCRIPTION,
 564     kOsWin,
 565     SINGLE_VALUE_TYPE(switches::kEnableTabGroupsContextMenu)
 566   },
 567   {
 568     "enable-instant-extended-api",
 569     IDS_FLAGS_ENABLE_INSTANT_EXTENDED_API,
 570     IDS_FLAGS_ENABLE_INSTANT_EXTENDED_API_DESCRIPTION,
 571     kOsDesktop,
 572     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableInstantExtendedAPI,
 573                               switches::kDisableInstantExtendedAPI)
 574   },
 575   {
 576     "enable-local-first-load-ntp",
 577     IDS_FLAGS_ENABLE_LOCAL_FIRST_LOAD_NTP,
 578     IDS_FLAGS_ENABLE_LOCAL_FIRST_LOAD_NTP_DESCRIPTION,
 579     kOsDesktop,
 580     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableLocalFirstLoadNTP,
 581                               switches::kDisableLocalFirstLoadNTP)
 582   },
 583   {
 584     "enable-local-only-instant-extended-api",
 585     IDS_FLAGS_ENABLE_LOCAL_ONLY_INSTANT_EXTENDED_API,
 586     IDS_FLAGS_ENABLE_LOCAL_ONLY_INSTANT_EXTENDED_API_DESCRIPTION,
 587     kOsDesktop,
 588     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableLocalOnlyInstantExtendedAPI,
 589                               switches::kDisableLocalOnlyInstantExtendedAPI)
 590   },
 591   {
 592     "static-ip-config",
 593     IDS_FLAGS_STATIC_IP_CONFIG_NAME,
 594     IDS_FLAGS_STATIC_IP_CONFIG_DESCRIPTION,
 595     kOsCrOS,
 596 #if defined(OS_CHROMEOS)
 597     // This switch exists only on Chrome OS.
 598     SINGLE_VALUE_TYPE(chromeos::switches::kEnableStaticIPConfig)
 599 #else
 600     SINGLE_VALUE_TYPE("")
 601 #endif
 602   },
 603   {
 604     "show-autofill-type-predictions",
 605     IDS_FLAGS_SHOW_AUTOFILL_TYPE_PREDICTIONS_NAME,
 606     IDS_FLAGS_SHOW_AUTOFILL_TYPE_PREDICTIONS_DESCRIPTION,
 607     kOsAll,
 608     SINGLE_VALUE_TYPE(autofill::switches::kShowAutofillTypePredictions)
 609   },
 610   {
 611     "enable-sync-favicons",
 612     IDS_FLAGS_ENABLE_SYNC_FAVICONS_NAME,
 613     IDS_FLAGS_ENABLE_SYNC_FAVICONS_DESCRIPTION,
 614     kOsAll,
 615     SINGLE_VALUE_TYPE(switches::kEnableSyncFavicons)
 616   },
 617   {
 618     "sync-keystore-encryption",
 619     IDS_FLAGS_SYNC_KEYSTORE_ENCRYPTION_NAME,
 620     IDS_FLAGS_SYNC_KEYSTORE_ENCRYPTION_DESCRIPTION,
 621     kOsAll,
 622     SINGLE_VALUE_TYPE(switches::kSyncKeystoreEncryption)
 623   },
 624   {
 625     "enable-gesture-tap-highlight",
 626     IDS_FLAGS_ENABLE_GESTURE_TAP_HIGHLIGHTING_NAME,
 627     IDS_FLAGS_ENABLE_GESTURE_TAP_HIGHLIGHTING_DESCRIPTION,
 628     kOsLinux | kOsCrOS,
 629     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableGestureTapHighlight,
 630                               switches::kDisableGestureTapHighlight)
 631   },
 632   {
 633     "enable-smooth-scrolling",  // FLAGS:RECORD_UMA
 634     IDS_FLAGS_ENABLE_SMOOTH_SCROLLING_NAME,
 635     IDS_FLAGS_ENABLE_SMOOTH_SCROLLING_DESCRIPTION,
 636     // Can't expose the switch unless the code is compiled in.
 637     // On by default for the Mac (different implementation in WebKit).
 638     kOsWin | kOsLinux,
 639     SINGLE_VALUE_TYPE(switches::kEnableSmoothScrolling)
 640   },
 641   {
 642     "omnibox-history-quick-provider-reorder-for-inlining",
 643     IDS_FLAGS_OMNIBOX_HISTORY_QUICK_PROVIDER_REORDER_FOR_INLINING_NAME,
 644     IDS_FLAGS_OMNIBOX_HISTORY_QUICK_PROVIDER_REORDER_FOR_INLINING_DESCRIPTION,
 645     kOsAll,
 646     MULTI_VALUE_TYPE(kOmniboxHistoryQuickProviderReorderForInliningChoices)
 647   },
 648   {
 649     "omnibox-inline-history-quick-provider",
 650     IDS_FLAGS_OMNIBOX_INLINE_HISTORY_QUICK_PROVIDER_NAME,
 651     IDS_FLAGS_OMNIBOX_INLINE_HISTORY_QUICK_PROVIDER_DESCRIPTION,
 652     kOsAll,
 653     MULTI_VALUE_TYPE(kOmniboxInlineHistoryQuickProviderChoices)
 654   },
 655   {
 656     "enable-panels",
 657     IDS_FLAGS_ENABLE_PANELS_NAME,
 658     IDS_FLAGS_ENABLE_PANELS_DESCRIPTION,
 659     kOsDesktop,
 660     SINGLE_VALUE_TYPE(switches::kEnablePanels)
 661   },
 662   {
 663     // See http://crbug.com/120416 for how to remove this flag.
 664     "save-page-as-mhtml",  // FLAGS:RECORD_UMA
 665     IDS_FLAGS_SAVE_PAGE_AS_MHTML_NAME,
 666     IDS_FLAGS_SAVE_PAGE_AS_MHTML_DESCRIPTION,
 667     kOsMac | kOsWin | kOsLinux,
 668     SINGLE_VALUE_TYPE(switches::kSavePageAsMHTML)
 669   },
 670   {
 671     "enable-autologin",
 672     IDS_FLAGS_ENABLE_AUTOLOGIN_NAME,
 673     IDS_FLAGS_ENABLE_AUTOLOGIN_DESCRIPTION,
 674     kOsMac | kOsWin | kOsLinux,
 675     SINGLE_VALUE_TYPE(switches::kEnableAutologin)
 676   },
 677   {
 678     "enable-spdy4a1",
 679     IDS_FLAGS_ENABLE_SPDY4A1_NAME,
 680     IDS_FLAGS_ENABLE_SPDY4A1_DESCRIPTION,
 681     kOsAll,
 682     SINGLE_VALUE_TYPE(switches::kEnableSpdy4a1)
 683   },
 684   {
 685     "enable-async-dns",
 686     IDS_FLAGS_ENABLE_ASYNC_DNS_NAME,
 687     IDS_FLAGS_ENABLE_ASYNC_DNS_DESCRIPTION,
 688     kOsWin | kOsMac | kOsLinux | kOsCrOS,
 689     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAsyncDns,
 690                               switches::kDisableAsyncDns)
 691   },
 692   {
 693     "disable-media-source",
 694     IDS_FLAGS_DISABLE_MEDIA_SOURCE_NAME,
 695     IDS_FLAGS_DISABLE_MEDIA_SOURCE_DESCRIPTION,
 696     kOsAll,
 697     SINGLE_VALUE_TYPE(switches::kDisableMediaSource)
 698   },
 699   {
 700     "disable-encrypted-media",
 701     IDS_FLAGS_DISABLE_ENCRYPTED_MEDIA_NAME,
 702     IDS_FLAGS_DISABLE_ENCRYPTED_MEDIA_DESCRIPTION,
 703     kOsDesktop,
 704     SINGLE_VALUE_TYPE(switches::kDisableEncryptedMedia)
 705   },
 706   {
 707     "enable-opus-playback",
 708     IDS_FLAGS_ENABLE_OPUS_PLAYBACK_NAME,
 709     IDS_FLAGS_ENABLE_OPUS_PLAYBACK_DESCRIPTION,
 710     kOsDesktop,
 711     SINGLE_VALUE_TYPE(switches::kEnableOpusPlayback)
 712   },
 713   {
 714     "enable-vp9-playback",
 715     IDS_FLAGS_ENABLE_VP9_PLAYBACK_NAME,
 716     IDS_FLAGS_ENABLE_VP9_PLAYBACK_DESCRIPTION,
 717     kOsDesktop,
 718     SINGLE_VALUE_TYPE(switches::kEnableVp9Playback)
 719   },
 720   {
 721     "enable-vp8-alpha-playback",
 722     IDS_FLAGS_ENABLE_VP8_ALPHA_PLAYBACK_NAME,
 723     IDS_FLAGS_ENABLE_VP8_ALPHA_PLAYBACK_DESCRIPTION,
 724     kOsDesktop,
 725     SINGLE_VALUE_TYPE(switches::kEnableVp8AlphaPlayback)
 726   },
 727   {
 728     "enable-managed-users",
 729     IDS_FLAGS_ENABLE_LOCALLY_MANAGED_USERS_NAME,
 730     IDS_FLAGS_ENABLE_LOCALLY_MANAGED_USERS_DESCRIPTION,
 731     kOsMac | kOsWin | kOsLinux | kOsAndroid | kOsCrOSOwnerOnly,
 732     SINGLE_VALUE_TYPE(switches::kEnableManagedUsers)
 733   },
 734 #if defined(USE_ASH)
 735   {
 736     "ash-disable-auto-maximizing",
 737     IDS_FLAGS_ASH_AUTO_MAXIMIZING_NAME,
 738     IDS_FLAGS_ASH_AUTO_MAXIMIZING_DESCRIPTION,
 739     kOsWin | kOsLinux | kOsCrOS,
 740     SINGLE_VALUE_TYPE(ash::switches::kAshDisableAutoMaximizing)
 741   },
 742   {
 743     "ash-disable-auto-window-placement",
 744     IDS_FLAGS_ASH_AUTO_WINDOW_PLACEMENT_NAME,
 745     IDS_FLAGS_ASH_AUTO_WINDOW_PLACEMENT_DESCRIPTION,
 746     kOsWin | kOsLinux | kOsCrOS,
 747     SINGLE_VALUE_TYPE(ash::switches::kAshDisableAutoWindowPlacement)
 748   },
 749   {
 750     "ash-disable-per-app-launcher",
 751     IDS_FLAGS_ASH_DISABLE_PER_APP_LAUNCHER_NAME,
 752     IDS_FLAGS_ASH_DISABLE_PER_APP_LAUNCHER_DESCRIPTION,
 753     kOsWin | kOsLinux | kOsCrOS,
 754     SINGLE_VALUE_TYPE(ash::switches::kAshDisablePerAppLauncher)
 755   },
 756 #endif
 757   {
 758     "per-tile-painting",
 759     IDS_FLAGS_PER_TILE_PAINTING_NAME,
 760     IDS_FLAGS_PER_TILE_PAINTING_DESCRIPTION,
 761     kOsMac | kOsLinux | kOsCrOS,
 762     SINGLE_VALUE_TYPE(cc::switches::kEnablePerTilePainting)
 763   },
 764   {
 765     "enable-javascript-harmony",
 766     IDS_FLAGS_ENABLE_JAVASCRIPT_HARMONY_NAME,
 767     IDS_FLAGS_ENABLE_JAVASCRIPT_HARMONY_DESCRIPTION,
 768     kOsAll,
 769     SINGLE_VALUE_TYPE_AND_VALUE(switches::kJavaScriptFlags, "--harmony")
 770   },
 771   {
 772     "enable-tab-browser-dragging",
 773     IDS_FLAGS_ENABLE_TAB_BROWSER_DRAGGING_NAME,
 774     IDS_FLAGS_ENABLE_TAB_BROWSER_DRAGGING_DESCRIPTION,
 775     kOsWin,
 776     SINGLE_VALUE_TYPE(switches::kTabBrowserDragging)
 777   },
 778   {
 779     "disable-restore-session-state",
 780     IDS_FLAGS_DISABLE_RESTORE_SESSION_STATE_NAME,
 781     IDS_FLAGS_DISABLE_RESTORE_SESSION_STATE_DESCRIPTION,
 782     kOsAll,
 783     SINGLE_VALUE_TYPE(switches::kDisableRestoreSessionState)
 784   },
 785   {
 786     "disable-software-rasterizer",
 787     IDS_FLAGS_DISABLE_SOFTWARE_RASTERIZER_NAME,
 788     IDS_FLAGS_DISABLE_SOFTWARE_RASTERIZER_DESCRIPTION,
 789 #if defined(ENABLE_SWIFTSHADER)
 790     kOsAll,
 791 #else
 792     0,
 793 #endif
 794     SINGLE_VALUE_TYPE(switches::kDisableSoftwareRasterizer)
 795   },
 796   {
 797     "enable-experimental-webkit-features",
 798     IDS_FLAGS_EXPERIMENTAL_WEBKIT_FEATURES_NAME,
 799     IDS_FLAGS_EXPERIMENTAL_WEBKIT_FEATURES_DESCRIPTION,
 800     kOsAll,
 801     SINGLE_VALUE_TYPE(switches::kEnableExperimentalWebKitFeatures)
 802   },
 803   {
 804     "enable-css-shaders",
 805     IDS_FLAGS_CSS_SHADERS_NAME,
 806     IDS_FLAGS_CSS_SHADERS_DESCRIPTION,
 807     kOsAll,
 808     SINGLE_VALUE_TYPE(switches::kEnableCssShaders)
 809   },
 810   {
 811     "enable-extension-activity-ui",
 812     IDS_FLAGS_ENABLE_EXTENSION_ACTIVITY_UI_NAME,
 813     IDS_FLAGS_ENABLE_EXTENSION_ACTIVITY_UI_DESCRIPTION,
 814     kOsDesktop,
 815     SINGLE_VALUE_TYPE(switches::kEnableExtensionActivityUI)
 816   },
 817   {
 818     "disable-ntp-other-sessions-menu",
 819     IDS_FLAGS_NTP_OTHER_SESSIONS_MENU_NAME,
 820     IDS_FLAGS_NTP_OTHER_SESSIONS_MENU_DESCRIPTION,
 821     kOsDesktop,
 822     SINGLE_VALUE_TYPE(switches::kDisableNTPOtherSessionsMenu)
 823   },
 824 #if defined(USE_ASH)
 825   {
 826     "enable-ash-oak",
 827     IDS_FLAGS_ENABLE_ASH_OAK_NAME,
 828     IDS_FLAGS_ENABLE_ASH_OAK_DESCRIPTION,
 829     kOsAll,
 830     SINGLE_VALUE_TYPE(ash::switches::kAshEnableOak),
 831   },
 832 #endif
 833   {
 834     "enable-devtools-experiments",
 835     IDS_FLAGS_ENABLE_DEVTOOLS_EXPERIMENTS_NAME,
 836     IDS_FLAGS_ENABLE_DEVTOOLS_EXPERIMENTS_DESCRIPTION,
 837     kOsDesktop,
 838     SINGLE_VALUE_TYPE(switches::kEnableDevToolsExperiments)
 839   },
 840   {
 841     "silent-debugger-extension-api",
 842     IDS_FLAGS_SILENT_DEBUGGER_EXTENSION_API_NAME,
 843     IDS_FLAGS_SILENT_DEBUGGER_EXTENSION_API_DESCRIPTION,
 844     kOsDesktop,
 845     SINGLE_VALUE_TYPE(switches::kSilentDebuggerExtensionAPI)
 846   },
 847   {
 848     "enable-suggestions-ntp",
 849     IDS_FLAGS_NTP_SUGGESTIONS_PAGE_NAME,
 850     IDS_FLAGS_NTP_SUGGESTIONS_PAGE_DESCRIPTION,
 851     kOsDesktop,
 852     SINGLE_VALUE_TYPE(switches::kEnableSuggestionsTabPage)
 853   },
 854   {
 855     "spellcheck-autocorrect",
 856     IDS_FLAGS_SPELLCHECK_AUTOCORRECT,
 857     IDS_FLAGS_SPELLCHECK_AUTOCORRECT_DESCRIPTION,
 858     kOsWin | kOsLinux | kOsCrOS,
 859     SINGLE_VALUE_TYPE(switches::kEnableSpellingAutoCorrect)
 860   },
 861   {
 862     "touch-events",
 863     IDS_TOUCH_EVENTS_NAME,
 864     IDS_TOUCH_EVENTS_DESCRIPTION,
 865     kOsDesktop,
 866     MULTI_VALUE_TYPE(kTouchEventsChoices)
 867   },
 868   {
 869     "touch-optimized-ui",
 870     IDS_FLAGS_TOUCH_OPTIMIZED_UI_NAME,
 871     IDS_FLAGS_TOUCH_OPTIMIZED_UI_DESCRIPTION,
 872     kOsWin,
 873     MULTI_VALUE_TYPE(kTouchOptimizedUIChoices)
 874   },
 875   {
 876     "disable-touch-adjustment",
 877     IDS_DISABLE_TOUCH_ADJUSTMENT_NAME,
 878     IDS_DISABLE_TOUCH_ADJUSTMENT_DESCRIPTION,
 879     kOsWin | kOsLinux | kOsCrOS,
 880     SINGLE_VALUE_TYPE(switches::kDisableTouchAdjustment)
 881   },
 882   {
 883     "enable-tab-capture",
 884     IDS_ENABLE_TAB_CAPTURE_NAME,
 885     IDS_ENABLE_TAB_CAPTURE_DESCRIPTION,
 886     kOsWin | kOsMac | kOsLinux | kOsCrOS,
 887     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(switches::kTabCapture, "1",
 888                                         switches::kTabCapture, "0")
 889   },
 890 #if defined(OS_CHROMEOS)
 891   {
 892     "enable-background-loader",
 893     IDS_ENABLE_BACKLOADER_NAME,
 894     IDS_ENABLE_BACKLOADER_DESCRIPTION,
 895     kOsCrOS,
 896     SINGLE_VALUE_TYPE(chromeos::switches::kEnableBackgroundLoader)
 897   },
 898   {
 899     "enable-bezel-touch",
 900     IDS_ENABLE_BEZEL_TOUCH_NAME,
 901     IDS_ENABLE_BEZEL_TOUCH_DESCRIPTION,
 902     kOsCrOS,
 903     SINGLE_VALUE_TYPE(switches::kEnableBezelTouch)
 904   },
 905   {
 906     "enable-screensaver-extension",
 907     IDS_ENABLE_SCREENSAVER_EXTENSION_NAME,
 908     IDS_ENABLE_SCREENSAVER_EXTENSION_DESCRIPTION,
 909     kOsCrOS,
 910     SINGLE_VALUE_TYPE(chromeos::switches::kEnableScreensaverExtensions)
 911   },
 912   {
 913     "no-discard-tabs",
 914     IDS_FLAGS_NO_DISCARD_TABS_NAME,
 915     IDS_FLAGS_NO_DISCARD_TABS_DESCRIPTION,
 916     kOsCrOS,
 917     SINGLE_VALUE_TYPE(chromeos::switches::kNoDiscardTabs)
 918   },
 919 #endif
 920   {
 921     "enable-download-resumption",
 922     IDS_FLAGS_ENABLE_DOWNLOAD_RESUMPTION_NAME,
 923     IDS_FLAGS_ENABLE_DOWNLOAD_RESUMPTION_DESCRIPTION,
 924     kOsDesktop,
 925     SINGLE_VALUE_TYPE(switches::kEnableDownloadResumption)
 926   },
 927   {
 928     "allow-nacl-socket-api",
 929     IDS_FLAGS_ALLOW_NACL_SOCKET_API_NAME,
 930     IDS_FLAGS_ALLOW_NACL_SOCKET_API_DESCRIPTION,
 931     kOsDesktop,
 932     SINGLE_VALUE_TYPE_AND_VALUE(switches::kAllowNaClSocketAPI, "*")
 933   },
 934   {
 935     "stacked-tab-strip",
 936     IDS_FLAGS_STACKED_TAB_STRIP_NAME,
 937     IDS_FLAGS_STACKED_TAB_STRIP_DESCRIPTION,
 938     kOsWin,
 939     SINGLE_VALUE_TYPE(switches::kEnableStackedTabStrip)
 940   },
 941   {
 942     "force-device-scale-factor",
 943     IDS_FLAGS_FORCE_HIGH_DPI_NAME,
 944     IDS_FLAGS_FORCE_HIGH_DPI_DESCRIPTION,
 945     kOsCrOS,
 946     SINGLE_VALUE_TYPE_AND_VALUE(switches::kForceDeviceScaleFactor, "2")
 947   },
 948 #if defined(OS_CHROMEOS)
 949   {
 950     "allow-touchpad-three-finger-click",
 951     IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_CLICK_NAME,
 952     IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_CLICK_DESCRIPTION,
 953     kOsCrOS,
 954     SINGLE_VALUE_TYPE(chromeos::switches::kEnableTouchpadThreeFingerClick)
 955   },
 956   {
 957     "allow-touchpad-three-finger-swipe",
 958     IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_SWIPE_NAME,
 959     IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_SWIPE_DESCRIPTION,
 960     kOsCrOS,
 961     SINGLE_VALUE_TYPE(chromeos::switches::kEnableTouchpadThreeFingerSwipe)
 962   },
 963 #endif
 964   {
 965     "use-client-login-signin-flow",
 966     IDS_FLAGS_USE_CLIENT_LOGIN_SIGNIN_FLOW_NAME,
 967     IDS_FLAGS_USE_CLIENT_LOGIN_SIGNIN_FLOW_DESCRIPTION,
 968     kOsMac | kOsWin | kOsLinux,
 969     SINGLE_VALUE_TYPE(switches::kUseClientLoginSigninFlow)
 970   },
 971   {
 972     "enable-desktop-guest-mode",
 973     IDS_FLAGS_DESKTOP_GUEST_MODE_NAME,
 974     IDS_FLAGS_DESKTOP_GUEST_MODE_DESCRIPTION,
 975     kOsMac | kOsWin | kOsLinux,
 976     SINGLE_VALUE_TYPE(switches::kEnableDesktopGuestMode)
 977   },
 978 #if defined(USE_ASH)
 979   {
 980     "show-launcher-alignment-menu",
 981     IDS_FLAGS_SHOW_LAUNCHER_ALIGNMENT_MENU_NAME,
 982     IDS_FLAGS_SHOW_LAUNCHER_ALIGNMENT_MENU_DESCRIPTION,
 983     kOsAll,
 984     SINGLE_VALUE_TYPE(switches::kShowLauncherAlignmentMenu)
 985   },
 986   {
 987     "disable-minimize-on-second-launcher-item-click",
 988     IDS_FLAGS_DISABLE_MINIMIZE_ON_SECOND_LAUNCHER_ITEM_CLICK_NAME,
 989     IDS_FLAGS_DISABLE_MINIMIZE_ON_SECOND_LAUNCHER_ITEM_CLICK_DESCRIPTION,
 990     kOsAll,
 991     SINGLE_VALUE_TYPE(switches::kDisableMinimizeOnSecondLauncherItemClick)
 992   },
 993   {
 994     "show-touch-hud",
 995     IDS_FLAGS_SHOW_TOUCH_HUD_NAME,
 996     IDS_FLAGS_SHOW_TOUCH_HUD_DESCRIPTION,
 997     kOsAll,
 998     SINGLE_VALUE_TYPE(ash::switches::kAshTouchHud)
 999   },
1000   {
1001     "enable-pinch",
1002     IDS_FLAGS_ENABLE_PINCH_SCALE_NAME,
1003     IDS_FLAGS_ENABLE_PINCH_SCALE_DESCRIPTION,
1004     kOsLinux | kOsWin | kOsCrOS,
1005     ENABLE_DISABLE_VALUE_TYPE(switches::kEnablePinch, switches::kDisablePinch),
1006   },
1007   {
1008     "pinch-zoom-scrollbars",
1009     IDS_FLAGS_PINCH_ZOOM_SCROLLBARS_NAME,
1010     IDS_FLAGS_PINCH_ZOOM_SCROLLBARS_DESCRIPTION,
1011     kOsCrOS,
1012     ENABLE_DISABLE_VALUE_TYPE(cc::switches::kEnablePinchZoomScrollbars,
1013                               cc::switches::kDisablePinchZoomScrollbars)
1014   },
1015   {
1016     "app-list-show-apps-only",
1017     IDS_FLAGS_ENABLE_APP_LIST_SHOW_APPS_ONLY_NAME,
1018     IDS_FLAGS_ENABLE_APP_LIST_SHOW_APPS_ONLY_DESCRIPTION,
1019     kOsAll,
1020     SINGLE_VALUE_TYPE(app_list::switches::kAppListShowAppsOnly),
1021   },
1022   {
1023     "forced-maximize-mode",
1024     IDS_FLAGS_FORCE_MAXIMIZE_MODE_NAME,
1025     IDS_FLAGS_FORCE_MAXIMIZE_MODE_DESCRIPTION,
1026     kOsLinux | kOsWin | kOsCrOS,
1027     SINGLE_VALUE_TYPE(ash::switches::kForcedMaximizeMode),
1028   },
1029 #endif  // defined(USE_ASH)
1030 #if defined(OS_CHROMEOS)
1031   {
1032     "disable-boot-animation",
1033     IDS_FLAGS_DISABLE_BOOT_ANIMATION,
1034     IDS_FLAGS_DISABLE_BOOT_ANIMATION_DESCRIPTION,
1035     kOsCrOSOwnerOnly,
1036     SINGLE_VALUE_TYPE(chromeos::switches::kDisableBootAnimation),
1037   },
1038   {
1039     "disable-boot-animation2",
1040     IDS_FLAGS_DISABLE_BOOT_ANIMATION2,
1041     IDS_FLAGS_DISABLE_BOOT_ANIMATION2_DESCRIPTION,
1042     kOsCrOSOwnerOnly,
1043     SINGLE_VALUE_TYPE(ash::switches::kAshDisableBootAnimation2),
1044   },
1045   {
1046     "boot-animation-fucntion",
1047     IDS_FLAGS_ASH_BOOT_ANIMATION_FUNCTION,
1048     IDS_FLAGS_ASH_BOOT_ANIMATION_FUNCTION_DESCRIPTION,
1049     kOsCrOSOwnerOnly,
1050     MULTI_VALUE_TYPE(kAshBootAnimationFunction),
1051   },
1052   {
1053     "captive-portal-detector",
1054     IDS_FLAGS_CAPTIVE_PORTAL_DETECTOR_NAME,
1055     IDS_FLAGS_CAPTIVE_PORTAL_DETECTOR_DESCRIPTION,
1056     kOsCrOSOwnerOnly,
1057     MULTI_VALUE_TYPE(kChromeCaptivePortalDetectionChoices),
1058   },
1059   {
1060     "disable-new-lock-animations",
1061     IDS_FLAGS_ASH_NEW_LOCK_ANIMATIONS,
1062     IDS_FLAGS_ASH_NEW_LOCK_ANIMATIONS_DESCRIPTION,
1063     kOsCrOS,
1064     SINGLE_VALUE_TYPE(ash::switches::kAshDisableNewLockAnimations),
1065   },
1066   {
1067     "file-manager-legacy",
1068     IDS_FLAGS_FILE_MANAGER_LEGACY_NAME,
1069     IDS_FLAGS_FILE_MANAGER_LEGACY_DESCRIPTION,
1070     kOsCrOS,
1071     SINGLE_VALUE_TYPE(chromeos::switches::kFileManagerLegacy),
1072   },
1073   {
1074     "file-manager-legacy-ui",
1075     IDS_FLAGS_FILE_MANAGER_LEGACY_UI_NAME,
1076     IDS_FLAGS_FILE_MANAGER_LEGACY_UI_DESCRIPTION,
1077     kOsCrOS,
1078     SINGLE_VALUE_TYPE(chromeos::switches::kFileManagerLegacyUI),
1079   },
1080   {
1081     "disable-app-mode",
1082     IDS_FLAGS_DISABLE_KIOSK_APPS_NAME,
1083     IDS_FLAGS_DISABLE_KIOSK_APPS_DESCRIPTION,
1084     kOsCrOSOwnerOnly,
1085     SINGLE_VALUE_TYPE(chromeos::switches::kDisableAppMode),
1086   },
1087   {
1088     "disable-force-fullscreen-app",
1089     IDS_FLAGS_DISABLE_FULLSCREEN_APP_NAME,
1090     IDS_FLAGS_DISABLE_FULLSCREEN_APP_DESCRIPTION,
1091     kOsCrOS,
1092     SINGLE_VALUE_TYPE(switches::kDisableFullscreenApp),
1093   },
1094   {
1095     "disable-quickoffice-component-app",
1096     IDS_FLAGS_DISABLE_QUICKOFFICE_COMPONENT_APP_NAME,
1097     IDS_FLAGS_DISABLE_QUICKOFFICE_COMPONENT_APP_DESCRIPTION,
1098     kOsCrOS,
1099     SINGLE_VALUE_TYPE(chromeos::switches::kDisableQuickofficeComponentApp),
1100   },
1101 #endif  // defined(OS_CHROMEOS)
1102   {
1103     "views-textfield",
1104     IDS_FLAGS_VIEWS_TEXTFIELD_NAME,
1105     IDS_FLAGS_VIEWS_TEXTFIELD_DESCRIPTION,
1106     kOsWin,
1107     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableViewsTextfield,
1108                               switches::kDisableViewsTextfield),
1109   },
1110   {
1111     "new-dialog-style",
1112     IDS_FLAGS_NEW_DIALOG_STYLE_NAME,
1113     IDS_FLAGS_NEW_DIALOG_STYLE_DESCRIPTION,
1114     kOsWin | kOsCrOS,
1115     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableNewDialogStyle,
1116                               switches::kDisableNewDialogStyle),
1117   },
1118   { "disable-accelerated-video-decode",
1119     IDS_FLAGS_DISABLE_ACCELERATED_VIDEO_DECODE_NAME,
1120     IDS_FLAGS_DISABLE_ACCELERATED_VIDEO_DECODE_DESCRIPTION,
1121     kOsWin | kOsCrOS,
1122     SINGLE_VALUE_TYPE(switches::kDisableAcceleratedVideoDecode),
1123   },
1124 #if defined(USE_ASH)
1125   {
1126     "ash-debug-shortcuts",
1127     IDS_FLAGS_DEBUG_SHORTCUTS_NAME,
1128     IDS_FLAGS_DEBUG_SHORTCUTS_DESCRIPTION,
1129     kOsAll,
1130     SINGLE_VALUE_TYPE(ash::switches::kAshDebugShortcuts),
1131   },
1132 #endif
1133   {
1134     "enable-contacts",
1135     IDS_FLAGS_ENABLE_CONTACTS_NAME,
1136     IDS_FLAGS_ENABLE_CONTACTS_DESCRIPTION,
1137     kOsCrOS,
1138     SINGLE_VALUE_TYPE(switches::kEnableContacts)
1139   },
1140 #if defined(USE_ASH)
1141   { "ash-enable-advanced-gestures",
1142     IDS_FLAGS_ENABLE_ADVANCED_GESTURES_NAME,
1143     IDS_FLAGS_ENABLE_ADVANCED_GESTURES_DESCRIPTION,
1144     kOsCrOS,
1145     SINGLE_VALUE_TYPE(ash::switches::kAshEnableAdvancedGestures),
1146   },
1147   { "ash-disable-tab-scrubbing",
1148     IDS_FLAGS_DISABLE_TAB_SCRUBBING_NAME,
1149     IDS_FLAGS_DISABLE_TAB_SCRUBBING_DESCRIPTION,
1150     kOsCrOS,
1151     SINGLE_VALUE_TYPE(switches::kAshDisableTabScrubbing),
1152   },
1153   { "ash-drag-and-drop-applist-to-launcher",
1154     IDS_FLAGS_DND_APPLIST_TO_LAUNCHER_NAME,
1155     IDS_FLAGS_DND_APPLIST_TO_LAUNCHER_DESCRIPTION,
1156     kOsCrOS,
1157     SINGLE_VALUE_TYPE(ash::switches::kAshDragAndDropAppListToLauncher),
1158   },
1159   { "ash-enable-workspace-scrubbing",
1160     IDS_FLAGS_ENABLE_WORKSPACE_SCRUBBING_NAME,
1161     IDS_FLAGS_ENABLE_WORKSPACE_SCRUBBING_DESCRIPTION,
1162     kOsCrOS,
1163     SINGLE_VALUE_TYPE(ash::switches::kAshEnableWorkspaceScrubbing),
1164   },
1165   { "ash-immersive-fullscreen-2",
1166     IDS_FLAGS_ASH_IMMERSIVE_FULLSCREEN_NAME,
1167     IDS_FLAGS_ASH_IMMERSIVE_FULLSCREEN_DESCRIPTION,
1168     kOsCrOS,
1169     ENABLE_DISABLE_VALUE_TYPE(ash::switches::kAshEnableImmersiveFullscreen,
1170                               ash::switches::kAshDisableImmersiveFullscreen),
1171   },
1172 #if defined(OS_LINUX)
1173   { "ash-enable-memory-monitor",
1174       IDS_FLAGS_ENABLE_MEMORY_MONITOR_NAME,
1175       IDS_FLAGS_ENABLE_MEMORY_MONITOR_DESCRIPTION,
1176       kOsCrOS,
1177       SINGLE_VALUE_TYPE(ash::switches::kAshEnableMemoryMonitor),
1178   },
1179 #endif
1180 #endif
1181 #if defined(OS_CHROMEOS)
1182   { "ash-disable-new-network-status-area",
1183     IDS_FLAGS_ASH_DISABLE_NEW_NETWORK_STATUS_AREA_NAME,
1184     IDS_FLAGS_ASH_DISABLE_NEW_NETWORK_STATUS_AREA_DESCRIPTION,
1185     kOsCrOS,
1186     SINGLE_VALUE_TYPE(ash::switches::kAshDisableNewNetworkStatusArea),
1187   },
1188   {
1189     "ash-enable-new-audio-handler2",
1190     IDS_FLAGS_ASH_ENABLE_NEW_AUDIO_HANDLER_NAME,
1191     IDS_FLAGS_ASH_ENABLE_NEW_AUDIO_HANDLER_DESCRIPTION,
1192     kOsCrOS,
1193     ENABLE_DISABLE_VALUE_TYPE("", ash::switches::kAshDisableNewAudioHandler)
1194   },
1195   {
1196     "ash-audio-device-menu",
1197     IDS_FLAGS_ASH_AUDIO_DEVICE_MENU_NAME,
1198     IDS_FLAGS_ASH_AUDIO_DEVICE_MENU_DESCRIPTION,
1199     kOsCrOS,
1200     SINGLE_VALUE_TYPE(ash::switches::kAshEnableAudioDeviceMenu)
1201   },
1202   {
1203     "enable-carrier-switching",
1204     IDS_FLAGS_ENABLE_CARRIER_SWITCHING,
1205     IDS_FLAGS_ENABLE_CARRIER_SWITCHING_DESCRIPTION,
1206     kOsCrOS,
1207     SINGLE_VALUE_TYPE(chromeos::switches::kEnableCarrierSwitching)
1208   },
1209   {
1210     "enable-request-tablet-site",
1211     IDS_FLAGS_ENABLE_REQUEST_TABLET_SITE_NAME,
1212     IDS_FLAGS_ENABLE_REQUEST_TABLET_SITE_DESCRIPTION,
1213     kOsCrOS,
1214     SINGLE_VALUE_TYPE(chromeos::switches::kEnableRequestTabletSite)
1215   },
1216 #endif
1217   {
1218     "debug-packed-apps",
1219     IDS_FLAGS_DEBUG_PACKED_APP_NAME,
1220     IDS_FLAGS_DEBUG_PACKED_APP_DESCRIPTION,
1221     kOsDesktop,
1222     SINGLE_VALUE_TYPE(switches::kDebugPackedApps)
1223   },
1224   {
1225     "enable-password-generation",
1226     IDS_FLAGS_ENABLE_PASSWORD_GENERATION_NAME,
1227     IDS_FLAGS_ENABLE_PASSWORD_GENERATION_DESCRIPTION,
1228     kOsDesktop,
1229     SINGLE_VALUE_TYPE(switches::kEnablePasswordGeneration)
1230   },
1231   {
1232     "enable-deferred-image-decoding",
1233     IDS_FLAGS_ENABLE_DEFERRED_IMAGE_DECODING_NAME,
1234     IDS_FLAGS_ENABLE_DEFERRED_IMAGE_DECODING_DESCRIPTION,
1235     kOsMac | kOsLinux | kOsCrOS,
1236     SINGLE_VALUE_TYPE(switches::kEnableDeferredImageDecoding)
1237   },
1238   {
1239     "performance-monitor-gathering",
1240     IDS_FLAGS_PERFORMANCE_MONITOR_GATHERING_NAME,
1241     IDS_FLAGS_PERFORMANCE_MONITOR_GATHERING_DESCRIPTION,
1242     kOsAll,
1243     SINGLE_VALUE_TYPE(switches::kPerformanceMonitorGathering)
1244   },
1245   {
1246     "disable-native-autofill-ui",
1247     IDS_FLAGS_DISABLE_NATIVE_AUTOFILL_UI_NAME,
1248     IDS_FLAGS_DISABLE_NATIVE_AUTOFILL_UI_DESCRIPTION,
1249     kOsDesktop,
1250     SINGLE_VALUE_TYPE(switches::kDisableNativeAutofillUi)
1251   },
1252   {
1253     "enable-experimental-form-filling",
1254     IDS_FLAGS_ENABLE_EXPERIMENTAL_FORM_FILLING_NAME,
1255     IDS_FLAGS_ENABLE_EXPERIMENTAL_FORM_FILLING_DESCRIPTION,
1256     kOsWin | kOsCrOS,
1257     SINGLE_VALUE_TYPE(autofill::switches::kEnableExperimentalFormFilling)
1258   },
1259   {
1260     "wallet-service-use-prod",
1261     IDS_FLAGS_ENABLE_WALLET_PRODUCTION_SERVICE_NAME,
1262     IDS_FLAGS_ENABLE_WALLET_PRODUCTION_SERVICE_DESCRIPTION,
1263     kOsCrOS | kOsWin,
1264     SINGLE_VALUE_TYPE(autofill::switches::kWalletServiceUseProd)
1265   },
1266   {
1267     "enable-interactive-autocomplete",
1268     IDS_FLAGS_ENABLE_INTERACTIVE_AUTOCOMPLETE_NAME,
1269     IDS_FLAGS_ENABLE_INTERACTIVE_AUTOCOMPLETE_DESCRIPTION,
1270     kOsWin | kOsCrOS | kOsAndroid,
1271     SINGLE_VALUE_TYPE(switches::kEnableInteractiveAutocomplete)
1272   },
1273 #if defined(USE_AURA)
1274   {
1275     "overscroll-history-navigation",
1276     IDS_FLAGS_OVERSCROLL_HISTORY_NAVIGATION_NAME,
1277     IDS_FLAGS_OVERSCROLL_HISTORY_NAVIGATION_DESCRIPTION,
1278     kOsAll,
1279     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
1280         switches::kOverscrollHistoryNavigation, "1",
1281         switches::kOverscrollHistoryNavigation, "0")
1282   },
1283 #endif
1284   {
1285     "enable-touch-drag-drop",
1286     IDS_FLAGS_ENABLE_TOUCH_DRAG_DROP_NAME,
1287     IDS_FLAGS_ENABLE_TOUCH_DRAG_DROP_DESCRIPTION,
1288     kOsWin | kOsCrOS,
1289     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTouchDragDrop,
1290                               switches::kDisableTouchDragDrop)
1291   },
1292   {
1293     "enable-touch-editing",
1294     IDS_FLAGS_ENABLE_TOUCH_EDITING_NAME,
1295     IDS_FLAGS_ENABLE_TOUCH_EDITING_DESCRIPTION,
1296     kOsCrOS,
1297     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTouchEditing,
1298                               switches::kDisableTouchEditing)
1299   },
1300 #if defined(ENABLE_MESSAGE_CENTER)
1301   {
1302     "enable-rich-notifications",
1303     IDS_FLAGS_ENABLE_RICH_NOTIFICATIONS_NAME,
1304     IDS_FLAGS_ENABLE_RICH_NOTIFICATIONS_DESCRIPTION,
1305     kOsWin | kOsCrOS | kOsMac,
1306     ENABLE_DISABLE_VALUE_TYPE(
1307         message_center::switches::kEnableRichNotifications,
1308         message_center::switches::kDisableRichNotifications)
1309   },
1310 #endif
1311   {
1312     "enable-sync-synced-notifications",
1313     IDS_FLAGS_ENABLE_SYNCED_NOTIFICATIONS_NAME,
1314     IDS_FLAGS_ENABLE_SYNCED_NOTIFICATIONS_DESCRIPTION,
1315     kOsWin | kOsCrOS,
1316     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSyncSyncedNotifications,
1317                               switches::kDisableSyncSyncedNotifications)
1318   },
1319   {
1320     "disable-full-history-sync",
1321     IDS_FLAGS_FULL_HISTORY_SYNC_NAME,
1322     IDS_FLAGS_FULL_HISTORY_SYNC_DESCRIPTION,
1323     kOsAll,
1324     SINGLE_VALUE_TYPE(switches::kHistoryDisableFullHistorySync)
1325   },
1326   {
1327     "enable-usermedia-screen-capture",
1328     IDS_FLAGS_ENABLE_SCREEN_CAPTURE_NAME,
1329     IDS_FLAGS_ENABLE_SCREEN_CAPTURE_DESCRIPTION,
1330     kOsDesktop,
1331     SINGLE_VALUE_TYPE(switches::kEnableUserMediaScreenCapturing)
1332   },
1333   {
1334     "enable-apps-devtool-app",
1335     IDS_FLAGS_ENABLE_APPS_DEVTOOL_APP_NAME,
1336     IDS_FLAGS_ENABLE_APPS_DEVTOOL_APP_DESCRIPTION,
1337     kOsDesktop,
1338     SINGLE_VALUE_TYPE(switches::kAppsDevtool)
1339   },
1340   {
1341     "impl-side-painting",
1342     IDS_FLAGS_IMPL_SIDE_PAINTING_NAME,
1343     IDS_FLAGS_IMPL_SIDE_PAINTING_DESCRIPTION,
1344     kOsAndroid | kOsLinux | kOsCrOS,
1345     MULTI_VALUE_TYPE(kImplSidePaintingChoices)
1346   },
1347   {
1348     "enable-websocket-experimental-implementation",
1349     IDS_FLAGS_ENABLE_EXPERIMENTAL_WEBSOCKET_NAME,
1350     IDS_FLAGS_ENABLE_EXPERIMENTAL_WEBSOCKET_DESCRIPTION,
1351     kOsAll,
1352     SINGLE_VALUE_TYPE(switches::kEnableExperimentalWebSocket)
1353   },
1354   {
1355     "max-tiles-for-interest-area",
1356     IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_NAME,
1357     IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_DESCRIPTION,
1358     kOsAndroid | kOsLinux | kOsCrOS,
1359     MULTI_VALUE_TYPE(kMaxTilesForInterestAreaChoices)
1360   },
1361   {
1362     "enable-offline-mode",
1363     IDS_FLAGS_ENABLE_OFFLINE_MODE_NAME,
1364     IDS_FLAGS_ENABLE_OFFLINE_MODE_DESCRIPTION,
1365     kOsAll,
1366     SINGLE_VALUE_TYPE(switches::kEnableOfflineCacheAccess)
1367   },
1368   {
1369     "default-tile-width",
1370     IDS_FLAGS_DEFAULT_TILE_WIDTH_NAME,
1371     IDS_FLAGS_DEFAULT_TILE_WIDTH_DESCRIPTION,
1372     kOsAll,
1373     MULTI_VALUE_TYPE(kDefaultTileWidthChoices)
1374   },
1375   {
1376     "default-tile-height",
1377     IDS_FLAGS_DEFAULT_TILE_HEIGHT_NAME,
1378     IDS_FLAGS_DEFAULT_TILE_HEIGHT_DESCRIPTION,
1379     kOsAll,
1380     MULTI_VALUE_TYPE(kDefaultTileHeightChoices)
1381   },
1382   // TODO(sky): ifdef needed until focus sorted out in DesktopNativeWidgetAura.
1383 #if !defined(USE_AURA)
1384   {
1385     "track-active-visit-time",
1386     IDS_FLAGS_TRACK_ACTIVE_VISIT_TIME_NAME,
1387     IDS_FLAGS_TRACK_ACTIVE_VISIT_TIME_DESCRIPTION,
1388     kOsWin,
1389     SINGLE_VALUE_TYPE(switches::kTrackActiveVisitTime)
1390   },
1391 #endif
1392 #if defined(OS_ANDROID)
1393   {
1394     "disable-gesture-requirement-for-media-playback",
1395     IDS_FLAGS_DISABLE_GESTURE_REQUIREMENT_FOR_MEDIA_PLAYBACK_NAME,
1396     IDS_FLAGS_DISABLE_GESTURE_REQUIREMENT_FOR_MEDIA_PLAYBACK_DESCRIPTION,
1397     kOsAndroid,
1398     SINGLE_VALUE_TYPE(switches::kDisableGestureRequirementForMediaPlayback)
1399   },
1400 #endif
1401 #if defined(OS_CHROMEOS)
1402   {
1403     "enable-experimental-bluetooth",
1404     IDS_FLAGS_ENABLE_EXPERIMENTAL_BLUETOOTH_NAME,
1405     IDS_FLAGS_ENABLE_EXPERIMENTAL_BLUETOOTH_DESCRIPTION,
1406     kOsCrOS,
1407     SINGLE_VALUE_TYPE(chromeos::switches::kEnableExperimentalBluetooth)
1408   },
1409 #endif
1410 #if defined(ENABLE_GOOGLE_NOW)
1411   {
1412     "enable-google-now",
1413     IDS_FLAGS_ENABLE_GOOGLE_NOW_INTEGRATION_NAME,
1414     IDS_FLAGS_ENABLE_GOOGLE_NOW_INTEGRATION_DESCRIPTION,
1415     kOsWin | kOsCrOS,
1416     SINGLE_VALUE_TYPE(switches::kEnableGoogleNowIntegration)
1417   },
1418 #endif
1419   {
1420     "enable-translate-alpha-languages",
1421     IDS_FLAGS_ENABLE_TRANSLATE_ALPHA_LANGUAGES_NAME,
1422     IDS_FLAGS_ENABLE_TRANSLATE_ALPHA_LANGUAGES_DESCRIPTION,
1423     kOsAll,
1424     SINGLE_VALUE_TYPE(switches::kEnableTranslateAlphaLanguages)
1425   },
1426 #if defined(OS_CHROMEOS)
1427   {
1428     "enable-virtual-keyboard",
1429     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_NAME,
1430     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_DESCRIPTION,
1431     kOsCrOS,
1432     SINGLE_VALUE_TYPE(keyboard::switches::kEnableVirtualKeyboard)
1433   },
1434 #endif
1435   {
1436     "enable-simple-cache-backend",
1437     IDS_FLAGS_ENABLE_SIMPLE_CACHE_BACKEND_NAME,
1438     IDS_FLAGS_ENABLE_SIMPLE_CACHE_BACKEND_DESCRIPTION,
1439     kOsAndroid,
1440     MULTI_VALUE_TYPE(kSimpleCacheBackendChoices)
1441   },
1442   {
1443     "enable-tcp-fast-open",
1444     IDS_FLAGS_ENABLE_TCP_FAST_OPEN_NAME,
1445     IDS_FLAGS_ENABLE_TCP_FAST_OPEN_DESCRIPTION,
1446     kOsLinux | kOsCrOS | kOsAndroid,
1447     SINGLE_VALUE_TYPE(switches::kEnableTcpFastOpen)
1448   },
1449   {
1450     "enable-webp-in-accept-header",
1451     IDS_FLAGS_ENABLE_WEBP_IN_ACCEPT_HEADER_NAME,
1452     IDS_FLAGS_ENABLE_WEBP_IN_ACCEPT_HEADER_DESCRIPTION,
1453     kOsAll,
1454     SINGLE_VALUE_TYPE(switches::kEnableWebPInAcceptHeader)
1455   },
1456   {
1457     "apps-use-native-frame",
1458     IDS_FLAGS_ENABLE_NATIVE_FRAMES_FOR_APPS_NAME,
1459     IDS_FLAGS_ENABLE_NATIVE_FRAMES_FOR_APPS_DESCRIPTION,
1460     kOsWin,
1461     SINGLE_VALUE_TYPE(switches::kAppsUseNativeFrame)
1462   },
1463   {
1464     "enable-syncfs-directory-operation",
1465     IDS_FLAGS_ENABLE_SYNC_DIRECTORY_OPERATION_NAME,
1466     IDS_FLAGS_ENABLE_SYNC_DIRECTORY_OPERATION_DESCRIPTION,
1467     kOsAll,
1468     SINGLE_VALUE_TYPE(switches::kSyncfsEnableDirectoryOperation),
1469   },
1470 };
1471
1472 const Experiment* experiments = kExperiments;
1473 size_t num_experiments = arraysize(kExperiments);
1474
1475 // Stores and encapsulates the little state that about:flags has.
1476 class FlagsState {
1477  public:
1478   FlagsState() : needs_restart_(false) {}
1479   void ConvertFlagsToSwitches(PrefService* prefs, CommandLine* command_line);
1480   bool IsRestartNeededToCommitChanges();
1481   void SetExperimentEnabled(
1482       PrefService* prefs, const std::string& internal_name, bool enable);
1483   void RemoveFlagsSwitches(
1484       std::map<std::string, CommandLine::StringType>* switch_list);
1485   void ResetAllFlags(PrefService* prefs);
1486   void reset();
1487
1488   // Returns the singleton instance of this class
1489   static FlagsState* GetInstance() {
1490     return Singleton<FlagsState>::get();
1491   }
1492
1493  private:
1494   bool needs_restart_;
1495   std::map<std::string, std::string> flags_switches_;
1496
1497   DISALLOW_COPY_AND_ASSIGN(FlagsState);
1498 };
1499
1500 // Extracts the list of enabled lab experiments from preferences and stores them
1501 // in a set.
1502 void GetEnabledFlags(const PrefService* prefs, std::set<std::string>* result) {
1503   const ListValue* enabled_experiments = prefs->GetList(
1504       prefs::kEnabledLabsExperiments);
1505   if (!enabled_experiments)
1506     return;
1507
1508   for (ListValue::const_iterator it = enabled_experiments->begin();
1509        it != enabled_experiments->end();
1510        ++it) {
1511     std::string experiment_name;
1512     if (!(*it)->GetAsString(&experiment_name)) {
1513       LOG(WARNING) << "Invalid entry in " << prefs::kEnabledLabsExperiments;
1514       continue;
1515     }
1516     result->insert(experiment_name);
1517   }
1518 }
1519
1520 // Takes a set of enabled lab experiments
1521 void SetEnabledFlags(
1522     PrefService* prefs, const std::set<std::string>& enabled_experiments) {
1523   ListPrefUpdate update(prefs, prefs::kEnabledLabsExperiments);
1524   ListValue* experiments_list = update.Get();
1525
1526   experiments_list->Clear();
1527   for (std::set<std::string>::const_iterator it = enabled_experiments.begin();
1528        it != enabled_experiments.end();
1529        ++it) {
1530     experiments_list->Append(new StringValue(*it));
1531   }
1532 }
1533
1534 // Adds the internal names for the specified experiment to |names|.
1535 void AddInternalName(const Experiment& e, std::set<std::string>* names) {
1536   if (e.type == Experiment::SINGLE_VALUE) {
1537     names->insert(e.internal_name);
1538   } else {
1539     DCHECK(e.type == Experiment::MULTI_VALUE ||
1540            e.type == Experiment::ENABLE_DISABLE_VALUE);
1541     for (int i = 0; i < e.num_choices; ++i)
1542       names->insert(e.NameForChoice(i));
1543   }
1544 }
1545
1546 // Confirms that an experiment is valid, used in a DCHECK in
1547 // SanitizeList below.
1548 bool ValidateExperiment(const Experiment& e) {
1549   switch (e.type) {
1550     case Experiment::SINGLE_VALUE:
1551       DCHECK_EQ(0, e.num_choices);
1552       DCHECK(!e.choices);
1553       break;
1554     case Experiment::MULTI_VALUE:
1555       DCHECK_GT(e.num_choices, 0);
1556       DCHECK(e.choices);
1557       DCHECK(e.choices[0].command_line_switch);
1558       DCHECK_EQ('\0', e.choices[0].command_line_switch[0]);
1559       break;
1560     case Experiment::ENABLE_DISABLE_VALUE:
1561       DCHECK_EQ(3, e.num_choices);
1562       DCHECK(!e.choices);
1563       DCHECK(e.command_line_switch);
1564       DCHECK(e.command_line_value);
1565       DCHECK(e.disable_command_line_switch);
1566       DCHECK(e.disable_command_line_value);
1567       break;
1568     default:
1569       NOTREACHED();
1570   }
1571   return true;
1572 }
1573
1574 // Removes all experiments from prefs::kEnabledLabsExperiments that are
1575 // unknown, to prevent this list to become very long as experiments are added
1576 // and removed.
1577 void SanitizeList(PrefService* prefs) {
1578   std::set<std::string> known_experiments;
1579   for (size_t i = 0; i < num_experiments; ++i) {
1580     DCHECK(ValidateExperiment(experiments[i]));
1581     AddInternalName(experiments[i], &known_experiments);
1582   }
1583
1584   std::set<std::string> enabled_experiments;
1585   GetEnabledFlags(prefs, &enabled_experiments);
1586
1587   std::set<std::string> new_enabled_experiments;
1588   std::set_intersection(
1589       known_experiments.begin(), known_experiments.end(),
1590       enabled_experiments.begin(), enabled_experiments.end(),
1591       std::inserter(new_enabled_experiments, new_enabled_experiments.begin()));
1592
1593   if (new_enabled_experiments != enabled_experiments)
1594     SetEnabledFlags(prefs, new_enabled_experiments);
1595 }
1596
1597 void GetSanitizedEnabledFlags(
1598     PrefService* prefs, std::set<std::string>* result) {
1599   SanitizeList(prefs);
1600   GetEnabledFlags(prefs, result);
1601 }
1602
1603 // Variant of GetSanitizedEnabledFlags that also removes any flags that aren't
1604 // enabled on the current platform.
1605 void GetSanitizedEnabledFlagsForCurrentPlatform(
1606     PrefService* prefs, std::set<std::string>* result) {
1607   GetSanitizedEnabledFlags(prefs, result);
1608
1609   // Filter out any experiments that aren't enabled on the current platform.  We
1610   // don't remove these from prefs else syncing to a platform with a different
1611   // set of experiments would be lossy.
1612   std::set<std::string> platform_experiments;
1613   int current_platform = GetCurrentPlatform();
1614   for (size_t i = 0; i < num_experiments; ++i) {
1615     if (experiments[i].supported_platforms & current_platform)
1616       AddInternalName(experiments[i], &platform_experiments);
1617 #if defined(OS_CHROMEOS)
1618     if (experiments[i].supported_platforms & kOsCrOSOwnerOnly)
1619       AddInternalName(experiments[i], &platform_experiments);
1620 #endif
1621   }
1622
1623   std::set<std::string> new_enabled_experiments;
1624   std::set_intersection(
1625       platform_experiments.begin(), platform_experiments.end(),
1626       result->begin(), result->end(),
1627       std::inserter(new_enabled_experiments, new_enabled_experiments.begin()));
1628
1629   result->swap(new_enabled_experiments);
1630 }
1631
1632 // Returns the Value representing the choice data in the specified experiment.
1633 Value* CreateChoiceData(const Experiment& experiment,
1634                         const std::set<std::string>& enabled_experiments) {
1635   DCHECK(experiment.type == Experiment::MULTI_VALUE ||
1636          experiment.type == Experiment::ENABLE_DISABLE_VALUE);
1637   ListValue* result = new ListValue;
1638   for (int i = 0; i < experiment.num_choices; ++i) {
1639     DictionaryValue* value = new DictionaryValue;
1640     const std::string name = experiment.NameForChoice(i);
1641     value->SetString("internal_name", name);
1642     value->SetString("description", experiment.DescriptionForChoice(i));
1643     value->SetBoolean("selected", enabled_experiments.count(name) > 0);
1644     result->Append(value);
1645   }
1646   return result;
1647 }
1648
1649 }  // namespace
1650
1651 std::string Experiment::NameForChoice(int index) const {
1652   DCHECK(type == Experiment::MULTI_VALUE ||
1653          type == Experiment::ENABLE_DISABLE_VALUE);
1654   DCHECK_LT(index, num_choices);
1655   return std::string(internal_name) + testing::kMultiSeparator +
1656          base::IntToString(index);
1657 }
1658
1659 string16 Experiment::DescriptionForChoice(int index) const {
1660   DCHECK(type == Experiment::MULTI_VALUE ||
1661          type == Experiment::ENABLE_DISABLE_VALUE);
1662   DCHECK_LT(index, num_choices);
1663   int description_id;
1664   if (type == Experiment::ENABLE_DISABLE_VALUE) {
1665     const int kEnableDisableDescriptionIds[] = {
1666       IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
1667       IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
1668       IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
1669     };
1670     description_id = kEnableDisableDescriptionIds[index];
1671   } else {
1672     description_id = choices[index].description_id;
1673   }
1674   return l10n_util::GetStringUTF16(description_id);
1675 }
1676
1677 void ConvertFlagsToSwitches(PrefService* prefs, CommandLine* command_line) {
1678   FlagsState::GetInstance()->ConvertFlagsToSwitches(prefs, command_line);
1679 }
1680
1681 ListValue* GetFlagsExperimentsData(PrefService* prefs, FlagAccess access) {
1682   std::set<std::string> enabled_experiments;
1683   GetSanitizedEnabledFlags(prefs, &enabled_experiments);
1684
1685   int current_platform = GetCurrentPlatform();
1686
1687   ListValue* experiments_data = new ListValue();
1688   for (size_t i = 0; i < num_experiments; ++i) {
1689     const Experiment& experiment = experiments[i];
1690
1691     DictionaryValue* data = new DictionaryValue();
1692     data->SetString("internal_name", experiment.internal_name);
1693     data->SetString("name",
1694                     l10n_util::GetStringUTF16(experiment.visible_name_id));
1695     data->SetString("description",
1696                     l10n_util::GetStringUTF16(
1697                         experiment.visible_description_id));
1698     bool supported = (experiment.supported_platforms & current_platform) != 0;
1699 #if defined(OS_CHROMEOS)
1700     if (access == kOwnerAccessToFlags &&
1701         (experiment.supported_platforms & kOsCrOSOwnerOnly) != 0)
1702       supported = true;
1703 #endif
1704     data->SetBoolean("supported", supported);
1705
1706     ListValue* supported_platforms = new ListValue();
1707     AddOsStrings(experiment.supported_platforms, supported_platforms);
1708     data->Set("supported_platforms", supported_platforms);
1709
1710     switch (experiment.type) {
1711       case Experiment::SINGLE_VALUE:
1712         data->SetBoolean(
1713             "enabled",
1714             enabled_experiments.count(experiment.internal_name) > 0);
1715         break;
1716       case Experiment::MULTI_VALUE:
1717       case Experiment::ENABLE_DISABLE_VALUE:
1718         data->Set("choices", CreateChoiceData(experiment, enabled_experiments));
1719         break;
1720       default:
1721         NOTREACHED();
1722     }
1723
1724     experiments_data->Append(data);
1725   }
1726   return experiments_data;
1727 }
1728
1729 bool IsRestartNeededToCommitChanges() {
1730   return FlagsState::GetInstance()->IsRestartNeededToCommitChanges();
1731 }
1732
1733 void SetExperimentEnabled(
1734     PrefService* prefs, const std::string& internal_name, bool enable) {
1735   FlagsState::GetInstance()->SetExperimentEnabled(prefs, internal_name, enable);
1736 }
1737
1738 void RemoveFlagsSwitches(
1739     std::map<std::string, CommandLine::StringType>* switch_list) {
1740   FlagsState::GetInstance()->RemoveFlagsSwitches(switch_list);
1741 }
1742
1743 void ResetAllFlags(PrefService* prefs) {
1744   FlagsState::GetInstance()->ResetAllFlags(prefs);
1745 }
1746
1747 int GetCurrentPlatform() {
1748 #if defined(OS_MACOSX)
1749   return kOsMac;
1750 #elif defined(OS_WIN)
1751   return kOsWin;
1752 #elif defined(OS_CHROMEOS)  // Needs to be before the OS_LINUX check.
1753   return kOsCrOS;
1754 #elif defined(OS_LINUX) || defined(OS_OPENBSD)
1755   return kOsLinux;
1756 #elif defined(OS_ANDROID)
1757   return kOsAndroid;
1758 #else
1759 #error Unknown platform
1760 #endif
1761 }
1762
1763 void RecordUMAStatistics(const PrefService* prefs) {
1764   std::set<std::string> flags;
1765   GetEnabledFlags(prefs, &flags);
1766   for (std::set<std::string>::iterator it = flags.begin(); it != flags.end();
1767        ++it) {
1768     std::string action("AboutFlags_");
1769     action += *it;
1770     content::RecordComputedAction(action);
1771   }
1772   // Since flag metrics are recorded every startup, add a tick so that the
1773   // stats can be made meaningful.
1774   if (flags.size())
1775     content::RecordAction(UserMetricsAction("AboutFlags_StartupTick"));
1776   content::RecordAction(UserMetricsAction("StartupTick"));
1777 }
1778
1779 //////////////////////////////////////////////////////////////////////////////
1780 // FlagsState implementation.
1781
1782 namespace {
1783
1784 typedef std::map<std::string, std::pair<std::string, std::string> >
1785     NameToSwitchAndValueMap;
1786
1787 void SetFlagToSwitchMapping(const std::string& key,
1788                             const std::string& switch_name,
1789                             const std::string& switch_value,
1790                             NameToSwitchAndValueMap* name_to_switch_map) {
1791   DCHECK(name_to_switch_map->end() == name_to_switch_map->find(key));
1792   (*name_to_switch_map)[key] = std::make_pair(switch_name, switch_value);
1793 }
1794
1795 void FlagsState::ConvertFlagsToSwitches(
1796     PrefService* prefs, CommandLine* command_line) {
1797   if (command_line->HasSwitch(switches::kNoExperiments))
1798     return;
1799
1800   std::set<std::string> enabled_experiments;
1801
1802   GetSanitizedEnabledFlagsForCurrentPlatform(prefs, &enabled_experiments);
1803
1804   NameToSwitchAndValueMap name_to_switch_map;
1805   for (size_t i = 0; i < num_experiments; ++i) {
1806     const Experiment& e = experiments[i];
1807     if (e.type == Experiment::SINGLE_VALUE) {
1808       SetFlagToSwitchMapping(e.internal_name, e.command_line_switch,
1809                              e.command_line_value, &name_to_switch_map);
1810     } else if (e.type == Experiment::MULTI_VALUE) {
1811       for (int j = 0; j < e.num_choices; ++j) {
1812         SetFlagToSwitchMapping(e.NameForChoice(j),
1813                                e.choices[j].command_line_switch,
1814                                e.choices[j].command_line_value,
1815                                &name_to_switch_map);
1816       }
1817     } else {
1818       DCHECK_EQ(e.type, Experiment::ENABLE_DISABLE_VALUE);
1819       SetFlagToSwitchMapping(e.NameForChoice(0), std::string(), std::string(),
1820                              &name_to_switch_map);
1821       SetFlagToSwitchMapping(e.NameForChoice(1), e.command_line_switch,
1822                              e.command_line_value, &name_to_switch_map);
1823       SetFlagToSwitchMapping(e.NameForChoice(2), e.disable_command_line_switch,
1824                              e.disable_command_line_value, &name_to_switch_map);
1825     }
1826   }
1827
1828   command_line->AppendSwitch(switches::kFlagSwitchesBegin);
1829   flags_switches_.insert(
1830       std::pair<std::string, std::string>(switches::kFlagSwitchesBegin,
1831                                           std::string()));
1832   for (std::set<std::string>::iterator it = enabled_experiments.begin();
1833        it != enabled_experiments.end();
1834        ++it) {
1835     const std::string& experiment_name = *it;
1836     NameToSwitchAndValueMap::const_iterator name_to_switch_it =
1837         name_to_switch_map.find(experiment_name);
1838     if (name_to_switch_it == name_to_switch_map.end()) {
1839       NOTREACHED();
1840       continue;
1841     }
1842
1843     const std::pair<std::string, std::string>&
1844         switch_and_value_pair = name_to_switch_it->second;
1845
1846     command_line->AppendSwitchASCII(switch_and_value_pair.first,
1847                                     switch_and_value_pair.second);
1848     flags_switches_[switch_and_value_pair.first] = switch_and_value_pair.second;
1849   }
1850   command_line->AppendSwitch(switches::kFlagSwitchesEnd);
1851   flags_switches_.insert(
1852       std::pair<std::string, std::string>(switches::kFlagSwitchesEnd,
1853                                           std::string()));
1854 }
1855
1856 bool FlagsState::IsRestartNeededToCommitChanges() {
1857   return needs_restart_;
1858 }
1859
1860 void FlagsState::SetExperimentEnabled(
1861     PrefService* prefs, const std::string& internal_name, bool enable) {
1862   size_t at_index = internal_name.find(testing::kMultiSeparator);
1863   if (at_index != std::string::npos) {
1864     DCHECK(enable);
1865     // We're being asked to enable a multi-choice experiment. Disable the
1866     // currently selected choice.
1867     DCHECK_NE(at_index, 0u);
1868     const std::string experiment_name = internal_name.substr(0, at_index);
1869     SetExperimentEnabled(prefs, experiment_name, false);
1870
1871     // And enable the new choice, if it is not the default first choice.
1872     if (internal_name != experiment_name + "@0") {
1873       std::set<std::string> enabled_experiments;
1874       GetSanitizedEnabledFlags(prefs, &enabled_experiments);
1875       needs_restart_ |= enabled_experiments.insert(internal_name).second;
1876       SetEnabledFlags(prefs, enabled_experiments);
1877     }
1878     return;
1879   }
1880
1881   std::set<std::string> enabled_experiments;
1882   GetSanitizedEnabledFlags(prefs, &enabled_experiments);
1883
1884   const Experiment* e = NULL;
1885   for (size_t i = 0; i < num_experiments; ++i) {
1886     if (experiments[i].internal_name == internal_name) {
1887       e = experiments + i;
1888       break;
1889     }
1890   }
1891   DCHECK(e);
1892
1893   if (e->type == Experiment::SINGLE_VALUE) {
1894     if (enable)
1895       needs_restart_ |= enabled_experiments.insert(internal_name).second;
1896     else
1897       needs_restart_ |= (enabled_experiments.erase(internal_name) > 0);
1898   } else {
1899     if (enable) {
1900       // Enable the first choice.
1901       needs_restart_ |= enabled_experiments.insert(e->NameForChoice(0)).second;
1902     } else {
1903       // Find the currently enabled choice and disable it.
1904       for (int i = 0; i < e->num_choices; ++i) {
1905         std::string choice_name = e->NameForChoice(i);
1906         if (enabled_experiments.find(choice_name) !=
1907             enabled_experiments.end()) {
1908           needs_restart_ = true;
1909           enabled_experiments.erase(choice_name);
1910           // Continue on just in case there's a bug and more than one
1911           // experiment for this choice was enabled.
1912         }
1913       }
1914     }
1915   }
1916
1917   SetEnabledFlags(prefs, enabled_experiments);
1918 }
1919
1920 void FlagsState::RemoveFlagsSwitches(
1921     std::map<std::string, CommandLine::StringType>* switch_list) {
1922   for (std::map<std::string, std::string>::const_iterator
1923            it = flags_switches_.begin(); it != flags_switches_.end(); ++it) {
1924     switch_list->erase(it->first);
1925   }
1926 }
1927
1928 void FlagsState::ResetAllFlags(PrefService* prefs) {
1929   needs_restart_ = true;
1930
1931   std::set<std::string> no_experiments;
1932   SetEnabledFlags(prefs, no_experiments);
1933 }
1934
1935 void FlagsState::reset() {
1936   needs_restart_ = false;
1937   flags_switches_.clear();
1938 }
1939
1940 }  // namespace
1941
1942 namespace testing {
1943
1944 // WARNING: '@' is also used in the html file. If you update this constant you
1945 // also need to update the html file.
1946 const char kMultiSeparator[] = "@";
1947
1948 void ClearState() {
1949   FlagsState::GetInstance()->reset();
1950 }
1951
1952 void SetExperiments(const Experiment* e, size_t count) {
1953   if (!e) {
1954     experiments = kExperiments;
1955     num_experiments = arraysize(kExperiments);
1956   } else {
1957     experiments = e;
1958     num_experiments = count;
1959   }
1960 }
1961
1962 const Experiment* GetExperiments(size_t* count) {
1963   *count = num_experiments;
1964   return experiments;
1965 }
1966
1967 }  // namespace testing
1968
1969 }  // namespace about_flags