Show singleton tab instead of opening multiple help tabs.

chrome/browser/ui/browser.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/browser.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // OS_WIN
@@ skipping 730 matching lines @@
 // static
 void Browser::OpenDownloadsWindow(Profile* profile) {
   Browser* browser = Browser::Create(profile);
   browser->ShowDownloadsTab();
   browser->window()->Show();
 }
 
 // static
 void Browser::OpenHelpWindow(Profile* profile) {
   Browser* browser = Browser::Create(profile);
-  browser->OpenHelpTab();
+  browser->ShowHelpTab();
   browser->window()->Show();
 }
 
 // static
 void Browser::OpenOptionsWindow(Profile* profile) {
   Browser* browser = Browser::Create(profile);
   browser->OpenOptionsDialog();
   browser->window()->Show();
 }
 
@@ skipping 1284 matching lines @@
 #else
   window_->ShowAboutChromeDialog();
 #endif
 }
 
 void Browser::OpenUpdateChromeDialog() {
   UserMetrics::RecordAction(UserMetricsAction("UpdateChrome"));
   window_->ShowUpdateChromeDialog();
 }
 
-void Browser::OpenHelpTab() {
+void Browser::ShowHelpTab() {
   GURL help_url(kHelpContentUrl);
   GURL localized_help_url = google_util::AppendGoogleLocaleParam(help_url);
-  AddSelectedTabWithURL(localized_help_url, PageTransition::AUTO_BOOKMARK);
+  ShowSingletonTab(localized_help_url);
 }
 
 void Browser::OpenThemeGalleryTabAndActivate() {
   AddSelectedTabWithURL(GURL(l10n_util::GetStringUTF8(IDS_THEMES_GALLERY_URL)),
                         PageTransition::LINK);
 }
 
 void Browser::OpenPrivacyDashboardTabAndActivate() {
   OpenURL(GURL(kPrivacyDashboardUrl), GURL(),
           NEW_FOREGROUND_TAB, PageTransition::LINK);
@@ skipping 406 matching lines @@
     case IDC_MANAGE_EXTENSIONS:     ShowExtensionsTab();              break;
     case IDC_SYNC_BOOKMARKS:        OpenSyncMyBookmarksDialog();      break;
     case IDC_OPTIONS:               OpenOptionsDialog();              break;
     case IDC_EDIT_SEARCH_ENGINES:   OpenSearchEngineOptionsDialog();  break;
     case IDC_VIEW_PASSWORDS:        OpenPasswordManager();            break;
     case IDC_CLEAR_BROWSING_DATA:   OpenClearBrowsingDataDialog();    break;
     case IDC_IMPORT_SETTINGS:       OpenImportSettingsDialog();       break;
     case IDC_ABOUT:                 OpenAboutChromeDialog();          break;
     case IDC_UPGRADE_DIALOG:        OpenUpdateChromeDialog();         break;
     case IDC_VIEW_INCOMPATIBILITIES: ShowAboutConflictsTab();         break;
-    case IDC_HELP_PAGE:             OpenHelpTab();                    break;
+    case IDC_HELP_PAGE:             ShowHelpTab();                    break;
 #if defined(OS_CHROMEOS)
     case IDC_FILE_MANAGER:          OpenFileManager();                break;
     case IDC_SYSTEM_OPTIONS:        OpenSystemOptionsDialog();        break;
     case IDC_INTERNET_OPTIONS:      OpenInternetOptionsDialog();      break;
     case IDC_LANGUAGE_OPTIONS:      OpenLanguageOptionsDialog();      break;
 #endif
 
     default:
       LOG(WARNING) << "Received Unimplemented Command: " << id;
       break;
@@ skipping 2229 matching lines @@
     // end up querying state once they process the tab switch.
     return;
   }
 
   BookmarkBar::AnimateChangeType animate_type =
       (reason == BOOKMARK_BAR_STATE_CHANGE_PREF_CHANGE) ?
       BookmarkBar::ANIMATE_STATE_CHANGE :
       BookmarkBar::DONT_ANIMATE_STATE_CHANGE;
   window_->BookmarkBarStateChanged(animate_type);
 }