chrome/browser/shell_integration_win.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/shell_integration.h"
   6
   7 #include <windows.h>
   8 #include <shlwapi.h>
   9 #include <shobjidl.h>
  10 #include <propkey.h>  // Needs to come after shobjidl.h.
  11
  12 #include "base/bind.h"
  13 #include "base/command_line.h"
  14 #include "base/files/file_enumerator.h"
  15 #include "base/files/file_util.h"
  16 #include "base/message_loop/message_loop.h"
  17 #include "base/path_service.h"
  18 #include "base/strings/string_number_conversions.h"
  19 #include "base/strings/string_util.h"
  20 #include "base/strings/stringprintf.h"
  21 #include "base/strings/utf_string_conversions.h"
  22 #include "base/win/registry.h"
  23 #include "base/win/scoped_comptr.h"
  24 #include "base/win/scoped_propvariant.h"
  25 #include "base/win/shortcut.h"
  26 #include "base/win/windows_version.h"
  27 #include "chrome/browser/policy/policy_path_parser.h"
  28 #include "chrome/browser/web_applications/web_app.h"
  29 #include "chrome/common/chrome_constants.h"
  30 #include "chrome/common/chrome_paths_internal.h"
  31 #include "chrome/common/chrome_switches.h"
  32 #include "chrome/installer/setup/setup_util.h"
  33 #include "chrome/installer/util/browser_distribution.h"
  34 #include "chrome/installer/util/create_reg_key_work_item.h"
  35 #include "chrome/installer/util/install_util.h"
  36 #include "chrome/installer/util/set_reg_value_work_item.h"
  37 #include "chrome/installer/util/shell_util.h"
  38 #include "chrome/installer/util/util_constants.h"
  39 #include "chrome/installer/util/work_item.h"
  40 #include "chrome/installer/util/work_item_list.h"
  41 #include "content/public/browser/browser_thread.h"
  42
  43 using content::BrowserThread;
  44
  45 namespace {
  46
  47 const wchar_t kAppListAppNameSuffix[] = L"AppList";
  48
  49 // Helper function for ShellIntegration::GetAppId to generates profile id
  50 // from profile path. "profile_id" is composed of sanitized basenames of
  51 // user data dir and profile dir joined by a ".".
  52 base::string16 GetProfileIdFromPath(const base::FilePath& profile_path) {
  53   // Return empty string if profile_path is empty
  54   if (profile_path.empty())
  55     return base::string16();
  56
  57   base::FilePath default_user_data_dir;
  58   // Return empty string if profile_path is in default user data
  59   // dir and is the default profile.
  60   if (chrome::GetDefaultUserDataDirectory(&default_user_data_dir) &&
  61       profile_path.DirName() == default_user_data_dir &&
  62       profile_path.BaseName().value() ==
  63           base::ASCIIToUTF16(chrome::kInitialProfile)) {
  64     return base::string16();
  65   }
  66
  67   // Get joined basenames of user data dir and profile.
  68   base::string16 basenames = profile_path.DirName().BaseName().value() +
  69       L"." + profile_path.BaseName().value();
  70
  71   base::string16 profile_id;
  72   profile_id.reserve(basenames.size());
  73
  74   // Generate profile_id from sanitized basenames.
  75   for (size_t i = 0; i < basenames.length(); ++i) {
  76     if (IsAsciiAlpha(basenames[i]) ||
  77         IsAsciiDigit(basenames[i]) ||
  78         basenames[i] == L'.')
  79       profile_id += basenames[i];
  80   }
  81
  82   return profile_id;
  83 }
  84
  85 base::string16 GetAppListAppName() {
  86   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
  87   base::string16 app_name(dist->GetBaseAppId());
  88   app_name.append(kAppListAppNameSuffix);
  89   return app_name;
  90 }
  91
  92 // Gets expected app id for given Chrome (based on |command_line| and
  93 // |is_per_user_install|).
  94 base::string16 GetExpectedAppId(const base::CommandLine& command_line,
  95                                 bool is_per_user_install) {
  96   base::FilePath user_data_dir;
  97   if (command_line.HasSwitch(switches::kUserDataDir))
  98     user_data_dir = command_line.GetSwitchValuePath(switches::kUserDataDir);
  99   else
 100     chrome::GetDefaultUserDataDirectory(&user_data_dir);
 101   // Adjust with any policy that overrides any other way to set the path.
 102   policy::path_parser::CheckUserDataDirPolicy(&user_data_dir);
 103   DCHECK(!user_data_dir.empty());
 104
 105   base::FilePath profile_subdir;
 106   if (command_line.HasSwitch(switches::kProfileDirectory)) {
 107     profile_subdir =
 108         command_line.GetSwitchValuePath(switches::kProfileDirectory);
 109   } else {
 110     profile_subdir =
 111         base::FilePath(base::ASCIIToUTF16(chrome::kInitialProfile));
 112   }
 113   DCHECK(!profile_subdir.empty());
 114
 115   base::FilePath profile_path = user_data_dir.Append(profile_subdir);
 116   base::string16 app_name;
 117   if (command_line.HasSwitch(switches::kApp)) {
 118     app_name = base::UTF8ToUTF16(web_app::GenerateApplicationNameFromURL(
 119         GURL(command_line.GetSwitchValueASCII(switches::kApp))));
 120   } else if (command_line.HasSwitch(switches::kAppId)) {
 121     app_name = base::UTF8ToUTF16(
 122         web_app::GenerateApplicationNameFromExtensionId(
 123             command_line.GetSwitchValueASCII(switches::kAppId)));
 124   } else if (command_line.HasSwitch(switches::kShowAppList)) {
 125     app_name = GetAppListAppName();
 126   } else {
 127     BrowserDistribution* dist = BrowserDistribution::GetDistribution();
 128     app_name = ShellUtil::GetBrowserModelId(dist, is_per_user_install);
 129   }
 130   DCHECK(!app_name.empty());
 131
 132   return ShellIntegration::GetAppModelIdForProfile(app_name, profile_path);
 133 }
 134
 135 void MigrateChromiumShortcutsCallback() {
 136   // This should run on the file thread.
 137   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 138
 139   // Get full path of chrome.
 140   base::FilePath chrome_exe;
 141   if (!PathService::Get(base::FILE_EXE, &chrome_exe))
 142     return;
 143
 144   // Locations to check for shortcuts migration.
 145   static const struct {
 146     int location_id;
 147     const wchar_t* sub_dir;
 148   } kLocations[] = {
 149     {
 150       base::DIR_TASKBAR_PINS,
 151       NULL
 152     }, {
 153       base::DIR_USER_DESKTOP,
 154       NULL
 155     }, {
 156       base::DIR_START_MENU,
 157       NULL
 158     }, {
 159       base::DIR_APP_DATA,
 160       L"Microsoft\\Internet Explorer\\Quick Launch\\User Pinned\\StartMenu"
 161     }
 162   };
 163
 164   for (int i = 0; i < arraysize(kLocations); ++i) {
 165     base::FilePath path;
 166     if (!PathService::Get(kLocations[i].location_id, &path)) {
 167       NOTREACHED();
 168       continue;
 169     }
 170
 171     if (kLocations[i].sub_dir)
 172       path = path.Append(kLocations[i].sub_dir);
 173
 174     bool check_dual_mode = (kLocations[i].location_id == base::DIR_START_MENU);
 175     ShellIntegration::MigrateShortcutsInPathInternal(chrome_exe, path,
 176                                                      check_dual_mode);
 177   }
 178 }
 179
 180 // Windows 8 introduced a new protocol->executable binding system which cannot
 181 // be retrieved in the HKCR registry subkey method implemented below. We call
 182 // AssocQueryString with the new Win8-only flag ASSOCF_IS_PROTOCOL instead.
 183 base::string16 GetAppForProtocolUsingAssocQuery(const GURL& url) {
 184   base::string16 url_scheme = base::ASCIIToUTF16(url.scheme());
 185   // Don't attempt to query protocol association on an empty string.
 186   if (url_scheme.empty())
 187     return base::string16();
 188
 189   // Query AssocQueryString for a human-readable description of the program
 190   // that will be invoked given the provided URL spec. This is used only to
 191   // populate the external protocol dialog box the user sees when invoking
 192   // an unknown external protocol.
 193   wchar_t out_buffer[1024];
 194   DWORD buffer_size = arraysize(out_buffer);
 195   HRESULT hr = AssocQueryString(ASSOCF_IS_PROTOCOL,
 196                                 ASSOCSTR_FRIENDLYAPPNAME,
 197                                 url_scheme.c_str(),
 198                                 NULL,
 199                                 out_buffer,
 200                                 &buffer_size);
 201   if (FAILED(hr)) {
 202     DLOG(WARNING) << "AssocQueryString failed!";
 203     return base::string16();
 204   }
 205   return base::string16(out_buffer);
 206 }
 207
 208 base::string16 GetAppForProtocolUsingRegistry(const GURL& url) {
 209   base::string16 url_spec = base::ASCIIToUTF16(url.possibly_invalid_spec());
 210   const base::string16 cmd_key_path =
 211       base::ASCIIToUTF16(url.scheme() + "\\shell\\open\\command");
 212   base::win::RegKey cmd_key(HKEY_CLASSES_ROOT,
 213                             cmd_key_path.c_str(),
 214                             KEY_READ);
 215   size_t split_offset = url_spec.find(L':');
 216   if (split_offset == base::string16::npos)
 217     return base::string16();
 218   const base::string16 parameters = url_spec.substr(split_offset + 1,
 219                                                     url_spec.length() - 1);
 220   base::string16 application_to_launch;
 221   if (cmd_key.ReadValue(NULL, &application_to_launch) == ERROR_SUCCESS) {
 222     ReplaceSubstringsAfterOffset(&application_to_launch,
 223                                  0,
 224                                  L"%1",
 225                                  parameters);
 226     return application_to_launch;
 227   }
 228   return base::string16();
 229 }
 230
 231
 232 ShellIntegration::DefaultWebClientState
 233     GetDefaultWebClientStateFromShellUtilDefaultState(
 234         ShellUtil::DefaultState default_state) {
 235   switch (default_state) {
 236     case ShellUtil::NOT_DEFAULT:
 237       return ShellIntegration::NOT_DEFAULT;
 238     case ShellUtil::IS_DEFAULT:
 239       return ShellIntegration::IS_DEFAULT;
 240     default:
 241       DCHECK_EQ(ShellUtil::UNKNOWN_DEFAULT, default_state);
 242       return ShellIntegration::UNKNOWN_DEFAULT;
 243   }
 244 }
 245
 246 }  // namespace
 247
 248 ShellIntegration::DefaultWebClientSetPermission
 249     ShellIntegration::CanSetAsDefaultBrowser() {
 250   BrowserDistribution* distribution = BrowserDistribution::GetDistribution();
 251   if (distribution->GetDefaultBrowserControlPolicy() !=
 252           BrowserDistribution::DEFAULT_BROWSER_FULL_CONTROL)
 253     return SET_DEFAULT_NOT_ALLOWED;
 254
 255   if (ShellUtil::CanMakeChromeDefaultUnattended())
 256     return SET_DEFAULT_UNATTENDED;
 257   else
 258     return SET_DEFAULT_INTERACTIVE;
 259 }
 260
 261 bool ShellIntegration::SetAsDefaultBrowser() {
 262   base::FilePath chrome_exe;
 263   if (!PathService::Get(base::FILE_EXE, &chrome_exe)) {
 264     LOG(ERROR) << "Error getting app exe path";
 265     return false;
 266   }
 267
 268   // From UI currently we only allow setting default browser for current user.
 269   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
 270   if (!ShellUtil::MakeChromeDefault(dist, ShellUtil::CURRENT_USER, chrome_exe,
 271                                     true /* elevate_if_not_admin */)) {
 272     LOG(ERROR) << "Chrome could not be set as default browser.";
 273     return false;
 274   }
 275
 276   VLOG(1) << "Chrome registered as default browser.";
 277   return true;
 278 }
 279
 280 bool ShellIntegration::SetAsDefaultProtocolClient(const std::string& protocol) {
 281   if (protocol.empty())
 282     return false;
 283
 284   base::FilePath chrome_exe;
 285   if (!PathService::Get(base::FILE_EXE, &chrome_exe)) {
 286     LOG(ERROR) << "Error getting app exe path";
 287     return false;
 288   }
 289
 290   base::string16 wprotocol(base::UTF8ToUTF16(protocol));
 291   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
 292   if (!ShellUtil::MakeChromeDefaultProtocolClient(dist, chrome_exe,
 293                                                   wprotocol)) {
 294     LOG(ERROR) << "Chrome could not be set as default handler for "
 295                << protocol << ".";
 296     return false;
 297   }
 298
 299   VLOG(1) << "Chrome registered as default handler for " << protocol << ".";
 300   return true;
 301 }
 302
 303 bool ShellIntegration::SetAsDefaultBrowserInteractive() {
 304   base::FilePath chrome_exe;
 305   if (!PathService::Get(base::FILE_EXE, &chrome_exe)) {
 306     NOTREACHED() << "Error getting app exe path";
 307     return false;
 308   }
 309
 310   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
 311   if (!ShellUtil::ShowMakeChromeDefaultSystemUI(dist, chrome_exe)) {
 312     LOG(ERROR) << "Failed to launch the set-default-browser Windows UI.";
 313     return false;
 314   }
 315
 316   VLOG(1) << "Set-default-browser Windows UI completed.";
 317   return true;
 318 }
 319
 320 bool ShellIntegration::SetAsDefaultProtocolClientInteractive(
 321     const std::string& protocol) {
 322   base::FilePath chrome_exe;
 323   if (!PathService::Get(base::FILE_EXE, &chrome_exe)) {
 324     NOTREACHED() << "Error getting app exe path";
 325     return false;
 326   }
 327
 328   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
 329   base::string16 wprotocol(base::UTF8ToUTF16(protocol));
 330   if (!ShellUtil::ShowMakeChromeDefaultProtocolClientSystemUI(dist, chrome_exe,
 331                                                               wprotocol)) {
 332     LOG(ERROR) << "Failed to launch the set-default-client Windows UI.";
 333     return false;
 334   }
 335
 336   VLOG(1) << "Set-default-client Windows UI completed.";
 337   return true;
 338 }
 339
 340 ShellIntegration::DefaultWebClientState ShellIntegration::GetDefaultBrowser() {
 341   return GetDefaultWebClientStateFromShellUtilDefaultState(
 342       ShellUtil::GetChromeDefaultState());
 343 }
 344
 345 ShellIntegration::DefaultWebClientState
 346     ShellIntegration::IsDefaultProtocolClient(const std::string& protocol) {
 347   return GetDefaultWebClientStateFromShellUtilDefaultState(
 348       ShellUtil::GetChromeDefaultProtocolClientState(
 349           base::UTF8ToUTF16(protocol)));
 350 }
 351
 352 base::string16 ShellIntegration::GetApplicationNameForProtocol(
 353     const GURL& url) {
 354   // Windows 8 or above requires a new protocol association query.
 355   if (base::win::GetVersion() >= base::win::VERSION_WIN8)
 356     return GetAppForProtocolUsingAssocQuery(url);
 357   else
 358     return GetAppForProtocolUsingRegistry(url);
 359 }
 360
 361 // There is no reliable way to say which browser is default on a machine (each
 362 // browser can have some of the protocols/shortcuts). So we look for only HTTP
 363 // protocol handler. Even this handler is located at different places in
 364 // registry on XP and Vista:
 365 // - HKCR\http\shell\open\command (XP)
 366 // - HKCU\Software\Microsoft\Windows\Shell\Associations\UrlAssociations\
 367 //   http\UserChoice (Vista)
 368 // This method checks if Firefox is defualt browser by checking these
 369 // locations and returns true if Firefox traces are found there. In case of
 370 // error (or if Firefox is not found)it returns the default value which
 371 // is false.
 372 bool ShellIntegration::IsFirefoxDefaultBrowser() {
 373   bool ff_default = false;
 374   if (base::win::GetVersion() >= base::win::VERSION_VISTA) {
 375     base::string16 app_cmd;
 376     base::win::RegKey key(HKEY_CURRENT_USER,
 377                           ShellUtil::kRegVistaUrlPrefs, KEY_READ);
 378     if (key.Valid() && (key.ReadValue(L"Progid", &app_cmd) == ERROR_SUCCESS) &&
 379         app_cmd == L"FirefoxURL")
 380       ff_default = true;
 381   } else {
 382     base::string16 key_path(L"http");
 383     key_path.append(ShellUtil::kRegShellOpen);
 384     base::win::RegKey key(HKEY_CLASSES_ROOT, key_path.c_str(), KEY_READ);
 385     base::string16 app_cmd;
 386     if (key.Valid() && (key.ReadValue(L"", &app_cmd) == ERROR_SUCCESS) &&
 387         base::string16::npos !=
 388         base::StringToLowerASCII(app_cmd).find(L"firefox"))
 389       ff_default = true;
 390   }
 391   return ff_default;
 392 }
 393
 394 base::string16 ShellIntegration::GetAppModelIdForProfile(
 395     const base::string16& app_name,
 396     const base::FilePath& profile_path) {
 397   std::vector<base::string16> components;
 398   components.push_back(app_name);
 399   const base::string16 profile_id(GetProfileIdFromPath(profile_path));
 400   if (!profile_id.empty())
 401     components.push_back(profile_id);
 402   return ShellUtil::BuildAppModelId(components);
 403 }
 404
 405 base::string16 ShellIntegration::GetChromiumModelIdForProfile(
 406     const base::FilePath& profile_path) {
 407   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
 408   base::FilePath chrome_exe;
 409   if (!PathService::Get(base::FILE_EXE, &chrome_exe)) {
 410     NOTREACHED();
 411     return dist->GetBaseAppId();
 412   }
 413   return GetAppModelIdForProfile(
 414       ShellUtil::GetBrowserModelId(dist,
 415                                    InstallUtil::IsPerUserInstall(chrome_exe)),
 416       profile_path);
 417 }
 418
 419 base::string16 ShellIntegration::GetAppListAppModelIdForProfile(
 420     const base::FilePath& profile_path) {
 421   return ShellIntegration::GetAppModelIdForProfile(
 422       GetAppListAppName(), profile_path);
 423 }
 424
 425 void ShellIntegration::MigrateChromiumShortcuts() {
 426   if (base::win::GetVersion() < base::win::VERSION_WIN7)
 427     return;
 428
 429   // This needs to happen eventually (e.g. so that the appid is fixed and the
 430   // run-time Chrome icon is merged with the taskbar shortcut), but this is not
 431   // urgent and shouldn't delay Chrome startup.
 432   static const int64 kMigrateChromiumShortcutsDelaySeconds = 15;
 433   BrowserThread::PostDelayedTask(
 434       BrowserThread::FILE, FROM_HERE,
 435       base::Bind(&MigrateChromiumShortcutsCallback),
 436       base::TimeDelta::FromSeconds(kMigrateChromiumShortcutsDelaySeconds));
 437 }
 438
 439 int ShellIntegration::MigrateShortcutsInPathInternal(
 440     const base::FilePath& chrome_exe,
 441     const base::FilePath& path,
 442     bool check_dual_mode) {
 443   DCHECK(base::win::GetVersion() >= base::win::VERSION_WIN7);
 444
 445   // Enumerate all pinned shortcuts in the given path directly.
 446   base::FileEnumerator shortcuts_enum(
 447       path, false,  // not recursive
 448       base::FileEnumerator::FILES, FILE_PATH_LITERAL("*.lnk"));
 449
 450   bool is_per_user_install = InstallUtil::IsPerUserInstall(chrome_exe);
 451
 452   int shortcuts_migrated = 0;
 453   base::FilePath target_path;
 454   base::string16 arguments;
 455   base::win::ScopedPropVariant propvariant;
 456   for (base::FilePath shortcut = shortcuts_enum.Next(); !shortcut.empty();
 457        shortcut = shortcuts_enum.Next()) {
 458     // TODO(gab): Use ProgramCompare instead of comparing FilePaths below once
 459     // it is fixed to work with FilePaths with spaces.
 460     if (!base::win::ResolveShortcut(shortcut, &target_path, &arguments) ||
 461         chrome_exe != target_path) {
 462       continue;
 463     }
 464     base::CommandLine command_line(
 465         base::CommandLine::FromString(base::StringPrintf(
 466             L"\"%ls\" %ls", target_path.value().c_str(), arguments.c_str())));
 467
 468     // Get the expected AppId for this Chrome shortcut.
 469     base::string16 expected_app_id(
 470         GetExpectedAppId(command_line, is_per_user_install));
 471     if (expected_app_id.empty())
 472       continue;
 473
 474     // Load the shortcut.
 475     base::win::ScopedComPtr<IShellLink> shell_link;
 476     base::win::ScopedComPtr<IPersistFile> persist_file;
 477     if (FAILED(shell_link.CreateInstance(CLSID_ShellLink, NULL,
 478                                          CLSCTX_INPROC_SERVER)) ||
 479         FAILED(persist_file.QueryFrom(shell_link.get())) ||
 480         FAILED(persist_file->Load(shortcut.value().c_str(), STGM_READ))) {
 481       DLOG(WARNING) << "Failed loading shortcut at " << shortcut.value();
 482       continue;
 483     }
 484
 485     // Any properties that need to be updated on the shortcut will be stored in
 486     // |updated_properties|.
 487     base::win::ShortcutProperties updated_properties;
 488
 489     // Validate the existing app id for the shortcut.
 490     base::win::ScopedComPtr<IPropertyStore> property_store;
 491     propvariant.Reset();
 492     if (FAILED(property_store.QueryFrom(shell_link.get())) ||
 493         property_store->GetValue(PKEY_AppUserModel_ID, propvariant.Receive()) !=
 494             S_OK) {
 495       // When in doubt, prefer not updating the shortcut.
 496       NOTREACHED();
 497       continue;
 498     } else {
 499       switch (propvariant.get().vt) {
 500         case VT_EMPTY:
 501           // If there is no app_id set, set our app_id if one is expected.
 502           if (!expected_app_id.empty())
 503             updated_properties.set_app_id(expected_app_id);
 504           break;
 505         case VT_LPWSTR:
 506           if (expected_app_id != base::string16(propvariant.get().pwszVal))
 507             updated_properties.set_app_id(expected_app_id);
 508           break;
 509         default:
 510           NOTREACHED();
 511           continue;
 512       }
 513     }
 514
 515     // Only set dual mode if the expected app id is the default app id.
 516     BrowserDistribution* dist = BrowserDistribution::GetDistribution();
 517     base::string16 default_chromium_model_id(
 518         ShellUtil::GetBrowserModelId(dist, is_per_user_install));
 519     if (check_dual_mode && expected_app_id == default_chromium_model_id) {
 520       propvariant.Reset();
 521       if (property_store->GetValue(PKEY_AppUserModel_IsDualMode,
 522                                    propvariant.Receive()) != S_OK) {
 523         // When in doubt, prefer to not update the shortcut.
 524         NOTREACHED();
 525         continue;
 526       } else {
 527         switch (propvariant.get().vt) {
 528           case VT_EMPTY:
 529             // If dual_mode is not set at all, make sure it gets set to true.
 530             updated_properties.set_dual_mode(true);
 531             break;
 532           case VT_BOOL:
 533             // If it is set to false, make sure it gets set to true as well.
 534             if (!propvariant.get().boolVal)
 535               updated_properties.set_dual_mode(true);
 536             break;
 537           default:
 538             NOTREACHED();
 539             continue;
 540         }
 541       }
 542     }
 543
 544     persist_file.Release();
 545     shell_link.Release();
 546
 547     // Update the shortcut if some of its properties need to be updated.
 548     if (updated_properties.options &&
 549         base::win::CreateOrUpdateShortcutLink(
 550             shortcut, updated_properties,
 551             base::win::SHORTCUT_UPDATE_EXISTING)) {
 552       ++shortcuts_migrated;
 553     }
 554   }
 555   return shortcuts_migrated;
 556 }
 557
 558 base::FilePath ShellIntegration::GetStartMenuShortcut(
 559     const base::FilePath& chrome_exe) {
 560   static const int kFolderIds[] = {
 561     base::DIR_COMMON_START_MENU,
 562     base::DIR_START_MENU,
 563   };
 564   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
 565   base::string16 shortcut_name(
 566       dist->GetShortcutName(BrowserDistribution::SHORTCUT_CHROME));
 567   base::FilePath shortcut;
 568
 569   // Check both the common and the per-user Start Menu folders for system-level
 570   // installs.
 571   size_t folder = InstallUtil::IsPerUserInstall(chrome_exe) ? 1 : 0;
 572   for (; folder < arraysize(kFolderIds); ++folder) {
 573     if (!PathService::Get(kFolderIds[folder], &shortcut)) {
 574       NOTREACHED();
 575       continue;
 576     }
 577
 578     shortcut = shortcut.Append(shortcut_name).Append(shortcut_name +
 579                                                      installer::kLnkExt);
 580     if (base::PathExists(shortcut))
 581       return shortcut;
 582   }
 583
 584   return base::FilePath();
 585 }