chrome/browser/ui/prefs/prefs_tab_helper.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/ui/prefs/prefs_tab_helper.h"
   6
   7 #include <string>
   8
   9 #include "base/prefs/overlay_user_pref_store.h"
  10 #include "base/prefs/pref_service.h"
  11 #include "base/strings/string_util.h"
  12 #include "base/strings/stringprintf.h"
  13 #include "base/strings/utf_string_conversions.h"
  14 #include "chrome/browser/browser_process.h"
  15 #include "chrome/browser/chrome_notification_types.h"
  16 #include "chrome/browser/profiles/profile.h"
  17 #include "chrome/browser/renderer_preferences_util.h"
  18 #include "chrome/browser/ui/zoom/chrome_zoom_level_prefs.h"
  19 #include "chrome/browser/ui/zoom/zoom_controller.h"
  20 #include "chrome/common/pref_font_webkit_names.h"
  21 #include "chrome/common/pref_names.h"
  22 #include "chrome/common/pref_names_util.h"
  23 #include "chrome/grit/locale_settings.h"
  24 #include "components/pref_registry/pref_registry_syncable.h"
  25 #include "content/public/browser/notification_details.h"
  26 #include "content/public/browser/notification_service.h"
  27 #include "content/public/browser/render_view_host.h"
  28 #include "content/public/browser/web_contents.h"
  29 #include "content/public/common/renderer_preferences.h"
  30 #include "content/public/common/web_preferences.h"
  31 #include "grit/platform_locale_settings.h"
  32 #include "third_party/icu/source/common/unicode/uchar.h"
  33 #include "third_party/icu/source/common/unicode/uscript.h"
  34 #include "ui/base/l10n/l10n_util.h"
  35
  36 #if defined(OS_POSIX) && !defined(OS_MACOSX) && defined(ENABLE_THEMES)
  37 #include "chrome/browser/themes/theme_service.h"
  38 #include "chrome/browser/themes/theme_service_factory.h"
  39 #endif
  40
  41 #if defined(OS_WIN)
  42 #include "base/win/windows_version.h"
  43 #endif
  44
  45 using content::WebContents;
  46 using content::WebPreferences;
  47
  48 DEFINE_WEB_CONTENTS_USER_DATA_KEY(PrefsTabHelper);
  49
  50 namespace {
  51
  52 // The list of prefs we want to observe.
  53 const char* kPrefsToObserve[] = {
  54   prefs::kDefaultCharset,
  55   prefs::kDisable3DAPIs,
  56   prefs::kEnableHyperlinkAuditing,
  57   prefs::kWebKitAllowDisplayingInsecureContent,
  58   prefs::kWebKitAllowRunningInsecureContent,
  59   prefs::kWebKitDefaultFixedFontSize,
  60   prefs::kWebKitDefaultFontSize,
  61   prefs::kWebKitDomPasteEnabled,
  62 #if defined(OS_ANDROID)
  63   prefs::kWebKitFontScaleFactor,
  64   prefs::kWebKitForceEnableZoom,
  65   prefs::kWebKitPasswordEchoEnabled,
  66 #endif
  67   prefs::kWebKitJavascriptCanOpenWindowsAutomatically,
  68   prefs::kWebKitJavascriptEnabled,
  69   prefs::kWebKitJavaEnabled,
  70   prefs::kWebKitLoadsImagesAutomatically,
  71   prefs::kWebKitMinimumFontSize,
  72   prefs::kWebKitMinimumLogicalFontSize,
  73   prefs::kWebKitPluginsEnabled,
  74   prefs::kWebKitShrinksStandaloneImagesToFit,
  75   prefs::kWebkitTabsToLinks,
  76   prefs::kWebKitTextAreasAreResizable,
  77   prefs::kWebKitUsesUniversalDetector,
  78   prefs::kWebKitWebSecurityEnabled,
  79 };
  80
  81 const int kPrefsToObserveLength = arraysize(kPrefsToObserve);
  82
  83 #if !defined(OS_ANDROID)
  84 // Registers a preference under the path |pref_name| for each script used for
  85 // per-script font prefs.
  86 // For example, for WEBKIT_WEBPREFS_FONTS_SERIF ("fonts.serif"):
  87 // "fonts.serif.Arab", "fonts.serif.Hang", etc. are registered.
  88 // |fonts_with_defaults| contains all |pref_names| already registered since they
  89 // have a specified default value.
  90 // On Android there are no default values for these properties and there is no
  91 // way to set them (because extensions are not supported so the Font Settings
  92 // API cannot be used), so we can avoid registering them altogether.
  93 void RegisterFontFamilyPrefs(user_prefs::PrefRegistrySyncable* registry,
  94                              const std::set<std::string>& fonts_with_defaults) {
  95
  96   // Expand the font concatenated with script name so this stays at RO memory
  97   // rather than allocated in heap.
  98   static const char* const kFontFamilyMap[] = {
  99 #define EXPAND_SCRIPT_FONT(map_name, script_name) map_name "." script_name,
 100
 101 #include "chrome/common/pref_font_script_names-inl.h"
 102 ALL_FONT_SCRIPTS(WEBKIT_WEBPREFS_FONTS_CURSIVE)
 103 ALL_FONT_SCRIPTS(WEBKIT_WEBPREFS_FONTS_FANTASY)
 104 ALL_FONT_SCRIPTS(WEBKIT_WEBPREFS_FONTS_FIXED)
 105 ALL_FONT_SCRIPTS(WEBKIT_WEBPREFS_FONTS_PICTOGRAPH)
 106 ALL_FONT_SCRIPTS(WEBKIT_WEBPREFS_FONTS_SANSERIF)
 107 ALL_FONT_SCRIPTS(WEBKIT_WEBPREFS_FONTS_SERIF)
 108 ALL_FONT_SCRIPTS(WEBKIT_WEBPREFS_FONTS_STANDARD)
 109
 110 #undef EXPAND_SCRIPT_FONT
 111   };
 112
 113   for (size_t i = 0; i < arraysize(kFontFamilyMap); ++i) {
 114     const char* pref_name = kFontFamilyMap[i];
 115     if (fonts_with_defaults.find(pref_name) == fonts_with_defaults.end()) {
 116       // We haven't already set a default value for this font preference, so set
 117       // an empty string as the default.
 118       registry->RegisterStringPref(
 119           pref_name,
 120           std::string(),
 121           user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 122     }
 123   }
 124 }
 125 #endif  // !defined(OS_ANDROID)
 126
 127 // Registers |obs| to observe per-script font prefs under the path |map_name|.
 128 // On android, there's no exposed way to change these prefs, so we can save
 129 // ~715KB of heap and some startup cycles by avoiding observing these prefs
 130 // since they will never change.
 131 void RegisterFontFamilyMapObserver(
 132     PrefChangeRegistrar* registrar,
 133     const char* map_name,
 134     const PrefChangeRegistrar::NamedChangeCallback& obs) {
 135   DCHECK(StartsWithASCII(map_name, "webkit.webprefs.", true));
 136   for (size_t i = 0; i < prefs::kWebKitScriptsForFontFamilyMapsLength; ++i) {
 137     const char* script = prefs::kWebKitScriptsForFontFamilyMaps[i];
 138     std::string pref_name = base::StringPrintf("%s.%s", map_name, script);
 139     registrar->Add(pref_name.c_str(), obs);
 140   }
 141 }
 142
 143 #if defined(OS_WIN)
 144 // On Windows with antialising we want to use an alternate fixed font like
 145 // Consolas, which looks much better than Courier New.
 146 bool ShouldUseAlternateDefaultFixedFont(const std::string& script) {
 147   if (!StartsWithASCII(script, "courier", false))
 148     return false;
 149   UINT smooth_type = 0;
 150   SystemParametersInfo(SPI_GETFONTSMOOTHINGTYPE, 0, &smooth_type, 0);
 151   return (base::win::GetVersion() >= base::win::VERSION_WIN7) &&
 152          (smooth_type == FE_FONTSMOOTHINGCLEARTYPE);
 153 }
 154 #endif
 155
 156 struct FontDefault {
 157   const char* pref_name;
 158   int resource_id;
 159 };
 160
 161 // Font pref defaults.  The prefs that have defaults vary by platform, since not
 162 // all platforms have fonts for all scripts for all generic families.
 163 // TODO(falken): add proper defaults when possible for all
 164 // platforms/scripts/generic families.
 165 const FontDefault kFontDefaults[] = {
 166   { prefs::kWebKitStandardFontFamily, IDS_STANDARD_FONT_FAMILY },
 167   { prefs::kWebKitFixedFontFamily, IDS_FIXED_FONT_FAMILY },
 168   { prefs::kWebKitSerifFontFamily, IDS_SERIF_FONT_FAMILY },
 169   { prefs::kWebKitSansSerifFontFamily, IDS_SANS_SERIF_FONT_FAMILY },
 170   { prefs::kWebKitCursiveFontFamily, IDS_CURSIVE_FONT_FAMILY },
 171   { prefs::kWebKitFantasyFontFamily, IDS_FANTASY_FONT_FAMILY },
 172   { prefs::kWebKitPictographFontFamily, IDS_PICTOGRAPH_FONT_FAMILY },
 173 #if defined(OS_CHROMEOS) || defined(OS_MACOSX) || defined(OS_WIN)
 174   { prefs::kWebKitStandardFontFamilyJapanese,
 175     IDS_STANDARD_FONT_FAMILY_JAPANESE },
 176   { prefs::kWebKitFixedFontFamilyJapanese, IDS_FIXED_FONT_FAMILY_JAPANESE },
 177   { prefs::kWebKitSerifFontFamilyJapanese, IDS_SERIF_FONT_FAMILY_JAPANESE },
 178   { prefs::kWebKitSansSerifFontFamilyJapanese,
 179     IDS_SANS_SERIF_FONT_FAMILY_JAPANESE },
 180   { prefs::kWebKitStandardFontFamilyKorean, IDS_STANDARD_FONT_FAMILY_KOREAN },
 181   { prefs::kWebKitSerifFontFamilyKorean, IDS_SERIF_FONT_FAMILY_KOREAN },
 182   { prefs::kWebKitSansSerifFontFamilyKorean,
 183     IDS_SANS_SERIF_FONT_FAMILY_KOREAN },
 184   { prefs::kWebKitStandardFontFamilySimplifiedHan,
 185     IDS_STANDARD_FONT_FAMILY_SIMPLIFIED_HAN },
 186   { prefs::kWebKitSerifFontFamilySimplifiedHan,
 187     IDS_SERIF_FONT_FAMILY_SIMPLIFIED_HAN },
 188   { prefs::kWebKitSansSerifFontFamilySimplifiedHan,
 189     IDS_SANS_SERIF_FONT_FAMILY_SIMPLIFIED_HAN },
 190   { prefs::kWebKitStandardFontFamilyTraditionalHan,
 191     IDS_STANDARD_FONT_FAMILY_TRADITIONAL_HAN },
 192   { prefs::kWebKitSerifFontFamilyTraditionalHan,
 193     IDS_SERIF_FONT_FAMILY_TRADITIONAL_HAN },
 194   { prefs::kWebKitSansSerifFontFamilyTraditionalHan,
 195     IDS_SANS_SERIF_FONT_FAMILY_TRADITIONAL_HAN },
 196 #endif
 197 #if defined(OS_CHROMEOS)
 198   { prefs::kWebKitStandardFontFamilyArabic, IDS_STANDARD_FONT_FAMILY_ARABIC },
 199   { prefs::kWebKitSerifFontFamilyArabic, IDS_SERIF_FONT_FAMILY_ARABIC },
 200   { prefs::kWebKitSansSerifFontFamilyArabic,
 201     IDS_SANS_SERIF_FONT_FAMILY_ARABIC },
 202   { prefs::kWebKitFixedFontFamilyKorean, IDS_FIXED_FONT_FAMILY_KOREAN },
 203   { prefs::kWebKitFixedFontFamilySimplifiedHan,
 204     IDS_FIXED_FONT_FAMILY_SIMPLIFIED_HAN },
 205   { prefs::kWebKitFixedFontFamilyTraditionalHan,
 206     IDS_FIXED_FONT_FAMILY_TRADITIONAL_HAN },
 207 #elif defined(OS_WIN)
 208   { prefs::kWebKitStandardFontFamilyCyrillic,
 209     IDS_STANDARD_FONT_FAMILY_CYRILLIC },
 210   { prefs::kWebKitFixedFontFamilyCyrillic, IDS_FIXED_FONT_FAMILY_CYRILLIC },
 211   { prefs::kWebKitSerifFontFamilyCyrillic, IDS_SERIF_FONT_FAMILY_CYRILLIC },
 212   { prefs::kWebKitSansSerifFontFamilyCyrillic,
 213     IDS_SANS_SERIF_FONT_FAMILY_CYRILLIC },
 214   { prefs::kWebKitStandardFontFamilyGreek, IDS_STANDARD_FONT_FAMILY_GREEK },
 215   { prefs::kWebKitFixedFontFamilyGreek, IDS_FIXED_FONT_FAMILY_GREEK },
 216   { prefs::kWebKitSerifFontFamilyGreek, IDS_SERIF_FONT_FAMILY_GREEK },
 217   { prefs::kWebKitSansSerifFontFamilyGreek, IDS_SANS_SERIF_FONT_FAMILY_GREEK },
 218   { prefs::kWebKitFixedFontFamilyKorean, IDS_FIXED_FONT_FAMILY_KOREAN },
 219   { prefs::kWebKitCursiveFontFamilyKorean, IDS_CURSIVE_FONT_FAMILY_KOREAN },
 220   { prefs::kWebKitFixedFontFamilySimplifiedHan,
 221     IDS_FIXED_FONT_FAMILY_SIMPLIFIED_HAN },
 222   { prefs::kWebKitFixedFontFamilyTraditionalHan,
 223     IDS_FIXED_FONT_FAMILY_TRADITIONAL_HAN },
 224 #endif
 225 };
 226
 227 const size_t kFontDefaultsLength = arraysize(kFontDefaults);
 228
 229 // Returns the script of the font pref |pref_name|.  For example, suppose
 230 // |pref_name| is "webkit.webprefs.fonts.serif.Hant".  Since the script code for
 231 // the script name "Hant" is USCRIPT_TRADITIONAL_HAN, the function returns
 232 // USCRIPT_TRADITIONAL_HAN.  |pref_name| must be a valid font pref name.
 233 UScriptCode GetScriptOfFontPref(const char* pref_name) {
 234   // ICU script names are four letters.
 235   static const size_t kScriptNameLength = 4;
 236
 237   size_t len = strlen(pref_name);
 238   DCHECK_GT(len, kScriptNameLength);
 239   const char* scriptName = &pref_name[len - kScriptNameLength];
 240   int32 code = u_getPropertyValueEnum(UCHAR_SCRIPT, scriptName);
 241   DCHECK(code >= 0 && code < USCRIPT_CODE_LIMIT);
 242   return static_cast<UScriptCode>(code);
 243 }
 244
 245 // If |scriptCode| is a member of a family of "similar" script codes, returns
 246 // the script code in that family that is used in font pref names.  For example,
 247 // USCRIPT_HANGUL and USCRIPT_KOREAN are considered equivalent for the purposes
 248 // of font selection.  Chrome uses the script code USCRIPT_HANGUL (script name
 249 // "Hang") in Korean font pref names (for example,
 250 // "webkit.webprefs.fonts.serif.Hang").  So, if |scriptCode| is USCRIPT_KOREAN,
 251 // the function returns USCRIPT_HANGUL.  If |scriptCode| is not a member of such
 252 // a family, returns |scriptCode|.
 253 UScriptCode GetScriptForFontPrefMatching(UScriptCode scriptCode) {
 254   switch (scriptCode) {
 255   case USCRIPT_HIRAGANA:
 256   case USCRIPT_KATAKANA:
 257   case USCRIPT_KATAKANA_OR_HIRAGANA:
 258     return USCRIPT_JAPANESE;
 259   case USCRIPT_KOREAN:
 260     return USCRIPT_HANGUL;
 261   default:
 262     return scriptCode;
 263   }
 264 }
 265
 266 // Returns the primary script used by the browser's UI locale.  For example, if
 267 // the locale is "ru", the function returns USCRIPT_CYRILLIC, and if the locale
 268 // is "en", the function returns USCRIPT_LATIN.
 269 UScriptCode GetScriptOfBrowserLocale() {
 270   std::string locale = g_browser_process->GetApplicationLocale();
 271
 272   // For Chinese locales, uscript_getCode() just returns USCRIPT_HAN but our
 273   // per-script fonts are for USCRIPT_SIMPLIFIED_HAN and
 274   // USCRIPT_TRADITIONAL_HAN.
 275   if (locale == "zh-CN")
 276     return USCRIPT_SIMPLIFIED_HAN;
 277   if (locale == "zh-TW")
 278     return USCRIPT_TRADITIONAL_HAN;
 279
 280   UScriptCode code = USCRIPT_INVALID_CODE;
 281   UErrorCode err = U_ZERO_ERROR;
 282   uscript_getCode(locale.c_str(), &code, 1, &err);
 283
 284   // Ignore the error that multiple scripts could be returned, since we only
 285   // want one script.
 286   if (U_FAILURE(err) && err != U_BUFFER_OVERFLOW_ERROR)
 287     code = USCRIPT_INVALID_CODE;
 288   return GetScriptForFontPrefMatching(code);
 289 }
 290
 291 // Sets a font family pref in |prefs| to |pref_value|.
 292 void OverrideFontFamily(WebPreferences* prefs,
 293                         const std::string& generic_family,
 294                         const std::string& script,
 295                         const std::string& pref_value) {
 296   content::ScriptFontFamilyMap* map = NULL;
 297   if (generic_family == "standard")
 298     map = &prefs->standard_font_family_map;
 299   else if (generic_family == "fixed")
 300     map = &prefs->fixed_font_family_map;
 301   else if (generic_family == "serif")
 302     map = &prefs->serif_font_family_map;
 303   else if (generic_family == "sansserif")
 304     map = &prefs->sans_serif_font_family_map;
 305   else if (generic_family == "cursive")
 306     map = &prefs->cursive_font_family_map;
 307   else if (generic_family == "fantasy")
 308     map = &prefs->fantasy_font_family_map;
 309   else if (generic_family == "pictograph")
 310     map = &prefs->pictograph_font_family_map;
 311   else
 312     NOTREACHED() << "Unknown generic font family: " << generic_family;
 313   (*map)[script] = base::UTF8ToUTF16(pref_value);
 314 }
 315
 316 }  // namespace
 317
 318 PrefsTabHelper::PrefsTabHelper(WebContents* contents)
 319     : web_contents_(contents),
 320       weak_ptr_factory_(this) {
 321   PrefService* prefs = GetProfile()->GetPrefs();
 322   pref_change_registrar_.Init(prefs);
 323   if (prefs) {
 324     // TODO(wjmaclean): Convert this to use the content-specific zoom-level
 325     // prefs when HostZoomMap moves to StoragePartition.
 326     chrome::ChromeZoomLevelPrefs* zoom_level_prefs =
 327         GetProfile()->GetZoomLevelPrefs();
 328
 329     base::Closure renderer_callback = base::Bind(
 330         &PrefsTabHelper::UpdateRendererPreferences, base::Unretained(this));
 331     // Incognito mode does not have a zoom_level_prefs, and not all tests
 332     // should need to create one either.
 333     if (zoom_level_prefs) {
 334       default_zoom_level_subscription_ =
 335           zoom_level_prefs->RegisterDefaultZoomLevelCallback(renderer_callback);
 336     }
 337     pref_change_registrar_.Add(prefs::kAcceptLanguages, renderer_callback);
 338     pref_change_registrar_.Add(prefs::kEnableDoNotTrack, renderer_callback);
 339     pref_change_registrar_.Add(prefs::kEnableReferrers, renderer_callback);
 340
 341 #if !defined(OS_MACOSX)
 342     pref_change_registrar_.Add(prefs::kFullscreenAllowed, renderer_callback);
 343 #endif
 344
 345     PrefChangeRegistrar::NamedChangeCallback webkit_callback = base::Bind(
 346         &PrefsTabHelper::OnWebPrefChanged, base::Unretained(this));
 347     for (int i = 0; i < kPrefsToObserveLength; ++i) {
 348       const char* pref_name = kPrefsToObserve[i];
 349       pref_change_registrar_.Add(pref_name, webkit_callback);
 350     }
 351
 352     RegisterFontFamilyMapObserver(&pref_change_registrar_,
 353                                   prefs::kWebKitStandardFontFamilyMap,
 354                                   webkit_callback);
 355     RegisterFontFamilyMapObserver(&pref_change_registrar_,
 356                                   prefs::kWebKitFixedFontFamilyMap,
 357                                   webkit_callback);
 358     RegisterFontFamilyMapObserver(&pref_change_registrar_,
 359                                   prefs::kWebKitSerifFontFamilyMap,
 360                                   webkit_callback);
 361     RegisterFontFamilyMapObserver(&pref_change_registrar_,
 362                                   prefs::kWebKitSansSerifFontFamilyMap,
 363                                   webkit_callback);
 364     RegisterFontFamilyMapObserver(&pref_change_registrar_,
 365                                   prefs::kWebKitCursiveFontFamilyMap,
 366                                   webkit_callback);
 367     RegisterFontFamilyMapObserver(&pref_change_registrar_,
 368                                   prefs::kWebKitFantasyFontFamilyMap,
 369                                   webkit_callback);
 370     RegisterFontFamilyMapObserver(&pref_change_registrar_,
 371                                   prefs::kWebKitPictographFontFamilyMap,
 372                                   webkit_callback);
 373   }
 374
 375   content::RendererPreferences* render_prefs =
 376       web_contents_->GetMutableRendererPrefs();
 377   renderer_preferences_util::UpdateFromSystemSettings(render_prefs,
 378                                                       GetProfile(),
 379                                                       web_contents_);
 380
 381 #if defined(OS_POSIX) && !defined(OS_MACOSX) && defined(ENABLE_THEMES)
 382   registrar_.Add(this,
 383                  chrome::NOTIFICATION_BROWSER_THEME_CHANGED,
 384                  content::Source<ThemeService>(
 385                      ThemeServiceFactory::GetForProfile(GetProfile())));
 386 #endif
 387 #if defined(USE_AURA)
 388   registrar_.Add(this,
 389                  chrome::NOTIFICATION_BROWSER_FLING_CURVE_PARAMETERS_CHANGED,
 390                  content::NotificationService::AllSources());
 391 #endif
 392 }
 393
 394 PrefsTabHelper::~PrefsTabHelper() {
 395 }
 396
 397 // static
 398 void PrefsTabHelper::InitIncognitoUserPrefStore(
 399     OverlayUserPrefStore* pref_store) {
 400   // List of keys that cannot be changed in the user prefs file by the incognito
 401   // profile.  All preferences that store information about the browsing history
 402   // or behavior of the user should have this property.
 403   pref_store->RegisterOverlayPref(prefs::kBrowserWindowPlacement);
 404   pref_store->RegisterOverlayPref(prefs::kSaveFileDefaultDirectory);
 405 #if defined(OS_ANDROID) || defined(OS_IOS)
 406   pref_store->RegisterOverlayPref(prefs::kProxy);
 407 #endif  // defined(OS_ANDROID) || defined(OS_IOS)
 408 }
 409
 410 // static
 411 void PrefsTabHelper::RegisterProfilePrefs(
 412     user_prefs::PrefRegistrySyncable* registry) {
 413   WebPreferences pref_defaults;
 414   registry->RegisterBooleanPref(
 415       prefs::kWebKitJavascriptEnabled,
 416       pref_defaults.javascript_enabled,
 417       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 418   registry->RegisterBooleanPref(
 419       prefs::kWebKitWebSecurityEnabled,
 420       pref_defaults.web_security_enabled,
 421       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 422   registry->RegisterBooleanPref(
 423       prefs::kWebKitJavascriptCanOpenWindowsAutomatically,
 424       true,
 425       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 426   registry->RegisterBooleanPref(
 427       prefs::kWebKitLoadsImagesAutomatically,
 428       pref_defaults.loads_images_automatically,
 429       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 430   registry->RegisterBooleanPref(
 431       prefs::kWebKitPluginsEnabled,
 432       pref_defaults.plugins_enabled,
 433       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 434   registry->RegisterBooleanPref(
 435       prefs::kWebKitDomPasteEnabled,
 436       pref_defaults.dom_paste_enabled,
 437       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 438   registry->RegisterBooleanPref(
 439       prefs::kWebKitShrinksStandaloneImagesToFit,
 440       pref_defaults.shrinks_standalone_images_to_fit,
 441       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 442   registry->RegisterBooleanPref(
 443       prefs::kWebKitTextAreasAreResizable,
 444       pref_defaults.text_areas_are_resizable,
 445       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 446   registry->RegisterBooleanPref(
 447       prefs::kWebKitJavaEnabled,
 448       pref_defaults.java_enabled,
 449       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 450   registry->RegisterBooleanPref(
 451       prefs::kWebkitTabsToLinks,
 452       pref_defaults.tabs_to_links,
 453       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 454   registry->RegisterBooleanPref(
 455       prefs::kWebKitAllowRunningInsecureContent,
 456       false,
 457       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 458   registry->RegisterBooleanPref(
 459       prefs::kWebKitAllowDisplayingInsecureContent,
 460       true,
 461       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 462   registry->RegisterBooleanPref(
 463       prefs::kEnableReferrers,
 464       true,
 465       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 466 #if defined(OS_ANDROID)
 467   registry->RegisterDoublePref(
 468       prefs::kWebKitFontScaleFactor,
 469       1.0,
 470       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 471   registry->RegisterBooleanPref(
 472       prefs::kWebKitForceEnableZoom,
 473       pref_defaults.force_enable_zoom,
 474       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 475   registry->RegisterBooleanPref(
 476       prefs::kWebKitPasswordEchoEnabled,
 477       pref_defaults.password_echo_enabled,
 478       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 479 #endif
 480   registry->RegisterLocalizedStringPref(
 481       prefs::kAcceptLanguages,
 482       IDS_ACCEPT_LANGUAGES,
 483       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 484   registry->RegisterLocalizedStringPref(
 485       prefs::kDefaultCharset,
 486       IDS_DEFAULT_ENCODING,
 487       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 488
 489   // Register font prefs that have defaults.
 490   std::set<std::string> fonts_with_defaults;
 491   UScriptCode browser_script = GetScriptOfBrowserLocale();
 492   for (size_t i = 0; i < kFontDefaultsLength; ++i) {
 493     FontDefault pref = kFontDefaults[i];
 494
 495 #if defined(OS_WIN)
 496     if (pref.pref_name == prefs::kWebKitFixedFontFamily) {
 497       if (ShouldUseAlternateDefaultFixedFont(
 498               l10n_util::GetStringUTF8(pref.resource_id)))
 499         pref.resource_id = IDS_FIXED_FONT_FAMILY_ALT_WIN;
 500     }
 501 #endif
 502
 503     UScriptCode pref_script = GetScriptOfFontPref(pref.pref_name);
 504
 505     // Suppress this default font pref value if it is for the primary script of
 506     // the browser's UI locale.  For example, if the pref is for the sans-serif
 507     // font for the Cyrillic script, and the browser locale is "ru" (Russian),
 508     // the default is suppressed.  Otherwise, the default would override the
 509     // user's font preferences when viewing pages in their native language.
 510     // This is because users have no way yet of customizing their per-script
 511     // font preferences.  The font prefs accessible in the options UI are for
 512     // the default, unknown script; these prefs have less priority than the
 513     // per-script font prefs when the script of the content is known.  This code
 514     // can possibly be removed later if users can easily access per-script font
 515     // prefs (e.g., via the extensions workflow), or the problem turns out to
 516     // not be really critical after all.
 517     if (browser_script != pref_script) {
 518       registry->RegisterLocalizedStringPref(
 519           pref.pref_name,
 520           pref.resource_id,
 521           user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 522       fonts_with_defaults.insert(pref.pref_name);
 523     }
 524   }
 525
 526   // Register per-script font prefs that don't have defaults.
 527 #if !defined(OS_ANDROID)
 528   RegisterFontFamilyPrefs(registry, fonts_with_defaults);
 529 #endif
 530
 531   registry->RegisterLocalizedIntegerPref(
 532       prefs::kWebKitDefaultFontSize,
 533       IDS_DEFAULT_FONT_SIZE,
 534       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 535   registry->RegisterLocalizedIntegerPref(
 536       prefs::kWebKitDefaultFixedFontSize,
 537       IDS_DEFAULT_FIXED_FONT_SIZE,
 538       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 539   registry->RegisterLocalizedIntegerPref(
 540       prefs::kWebKitMinimumFontSize,
 541       IDS_MINIMUM_FONT_SIZE,
 542       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 543   registry->RegisterLocalizedIntegerPref(
 544       prefs::kWebKitMinimumLogicalFontSize,
 545       IDS_MINIMUM_LOGICAL_FONT_SIZE,
 546       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 547   registry->RegisterLocalizedBooleanPref(
 548       prefs::kWebKitUsesUniversalDetector,
 549       IDS_USES_UNIVERSAL_DETECTOR,
 550       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 551   registry->RegisterLocalizedStringPref(
 552       prefs::kStaticEncodings,
 553       IDS_STATIC_ENCODING_LIST,
 554       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 555   registry->RegisterStringPref(
 556       prefs::kRecentlySelectedEncoding,
 557       std::string(),
 558       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 559 }
 560
 561 void PrefsTabHelper::Observe(int type,
 562                              const content::NotificationSource& source,
 563                              const content::NotificationDetails& details) {
 564 #if defined(OS_POSIX) && !defined(OS_MACOSX) && defined(ENABLE_THEMES)
 565   if (type == chrome::NOTIFICATION_BROWSER_THEME_CHANGED) {
 566     UpdateRendererPreferences();
 567     return;
 568   }
 569 #endif
 570
 571 #if defined(USE_AURA)
 572   if (type == chrome::NOTIFICATION_BROWSER_FLING_CURVE_PARAMETERS_CHANGED) {
 573     UpdateRendererPreferences();
 574     return;
 575   }
 576 #endif  // defined(USE_AURA)
 577
 578   NOTREACHED();
 579 }
 580
 581 void PrefsTabHelper::UpdateWebPreferences() {
 582   web_contents_->GetRenderViewHost()->UpdateWebkitPreferences(
 583       web_contents_->GetRenderViewHost()->GetWebkitPreferences());
 584 }
 585
 586 void PrefsTabHelper::UpdateRendererPreferences() {
 587   content::RendererPreferences* prefs =
 588       web_contents_->GetMutableRendererPrefs();
 589   renderer_preferences_util::UpdateFromSystemSettings(
 590       prefs, GetProfile(), web_contents_);
 591   web_contents_->GetRenderViewHost()->SyncRendererPrefs();
 592 }
 593
 594 Profile* PrefsTabHelper::GetProfile() {
 595   return Profile::FromBrowserContext(web_contents_->GetBrowserContext());
 596 }
 597
 598 void PrefsTabHelper::OnFontFamilyPrefChanged(const std::string& pref_name) {
 599   // When a font family pref's value goes from non-empty to the empty string, we
 600   // must add it to the usual WebPreferences struct passed to the renderer.
 601   //
 602   // The empty string means to fall back to the pref for the Common script
 603   // ("Zyyy").  For example, if chrome.fonts.serif.Cyrl is the empty string, it
 604   // means to use chrome.fonts.serif.Zyyy for Cyrillic script. Prefs that are
 605   // the empty string are normally not passed to WebKit, since there are so many
 606   // of them that it would cause a performance regression. Not passing the pref
 607   // is normally okay since WebKit does the desired fallback behavior regardless
 608   // of whether the empty string is passed or the pref is not passed at all. But
 609   // if the pref has changed from non-empty to the empty string, we must let
 610   // WebKit know.
 611   std::string generic_family;
 612   std::string script;
 613   if (pref_names_util::ParseFontNamePrefPath(pref_name,
 614                                              &generic_family,
 615                                              &script)) {
 616     PrefService* prefs = GetProfile()->GetPrefs();
 617     std::string pref_value = prefs->GetString(pref_name.c_str());
 618     if (pref_value.empty()) {
 619       WebPreferences web_prefs =
 620           web_contents_->GetRenderViewHost()->GetWebkitPreferences();
 621       OverrideFontFamily(&web_prefs, generic_family, script, std::string());
 622       web_contents_->GetRenderViewHost()->UpdateWebkitPreferences(web_prefs);
 623       return;
 624     }
 625   }
 626 }
 627
 628 void PrefsTabHelper::OnWebPrefChanged(const std::string& pref_name) {
 629 #if !defined(OS_ANDROID)
 630   OnFontFamilyPrefChanged(pref_name);
 631 #endif
 632
 633   web_contents_->GetRenderViewHost()->OnWebkitPreferencesChanged();
 634 }