Mostly cleanup.

* Use temporary variables when we're going to call AsWebContents() repeatedly
* Remove some NOTREACHED()s that don't really help debugging (and none of the surrounding code checks)
* Try and simplify or make clearer some bits of code

Also enables/disables some commands more selectively: IDC_GO is now enabled only when the go button is visible (i.e. when we're not loading), and several commands whose UI is only available in normal windows are now only enabled in normal windows.  This last change fixes a number of weird effects where you could hit different shortcuts in web app and popup windows and trigger commands with little or no UI feedback.
Review URL: http://codereview.chromium.org/14182

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7141 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 107 insertions, 136 deletions

diff --git a/chrome/browser/browser.cc b/chrome/browser/browser.cc
index ea85e3b..87b3e9e 100644
--- a/chrome/browser/browser.cc
+++ b/chrome/browser/browser.cc
@@ -392,14 +392,6 @@ std::wstring Browser::GetCurrentPageTitle() const {
   return l10n_util::GetStringF(IDS_BROWSER_WINDOW_TITLE_FORMAT, title);
 }
 
-bool Browser::IsCurrentPageLoading() const {
-  // GetSelectedTabContents can return NULL for example under Purify when
-  // the animations are running slowly and this function is called on a timer
-  // through LoadingAnimationCallback.
-  TabContents* tab_contents = GetSelectedTabContents();
-  return tab_contents && tab_contents->is_loading();
-}
-
 // static
 void Browser::FormatTitleForDisplay(std::wstring* title) {
   size_t current_index = 0;
@@ -489,8 +481,9 @@ TabContents* Browser::AddWebApplicationTab(Profile* profile,
   TabContents* contents =
       CreateTabContentsForURL(web_app->url(), GURL(), profile,
                               PageTransition::LINK, lazy, NULL);
-  if (contents->AsWebContents())
-    contents->AsWebContents()->SetWebApp(web_app);
+  WebContents* web_contents = contents->AsWebContents();
+  if (web_contents)
+    web_contents->SetWebApp(web_app);
 
   if (lazy) {
     contents->controller()->LoadURLLazily(
@@ -704,12 +697,6 @@ void Browser::RestoreTab() {
 
 void Browser::ConvertPopupToTabbedBrowser() {
   UserMetrics::RecordAction(L"ShowAsTab", profile_);
-
-  if (type() != TYPE_NORMAL) {
-    NOTREACHED();
-    return;
-  }
-
   int tab_strip_index = tabstrip_model_.selected_index();
   TabContents* contents = tabstrip_model_.DetachTabContentsAt(tab_strip_index);
   Browser* browser = Browser::Create(profile_);
@@ -723,13 +710,6 @@ void Browser::Exit() {
 }
 
 void Browser::BookmarkCurrentPage() {
-  if (type() != TYPE_NORMAL) {
-    // We disable bookmarking for types other than normal and shouldn't get
-    // here.
-    NOTREACHED();
-    return;
-  }
-
   UserMetrics::RecordAction(L"Star", profile_);
 
   TabContents* tab = GetSelectedTabContents();
@@ -805,9 +785,9 @@ void Browser::OverrideEncoding(int encoding_id) {
   UserMetrics::RecordAction(L"OverrideEncoding", profile_);
   const std::wstring selected_encoding =
       CharacterEncoding::GetCanonicalEncodingNameByCommandId(encoding_id);
-  TabContents* current_tab = GetSelectedTabContents();
-  if (!selected_encoding.empty() && current_tab->AsWebContents())
-     current_tab->AsWebContents()->override_encoding(selected_encoding);
+  WebContents* current_web_contents = GetSelectedTabContents()->AsWebContents();
+  if (!selected_encoding.empty() && current_web_contents)
+     current_web_contents->override_encoding(selected_encoding);
   // Update the list of recently selected encodings.
   std::wstring new_selected_encoding_list;
   if (CharacterEncoding::UpdateRecentlySelectdEncoding(
@@ -952,9 +932,8 @@ void Browser::OpenDebuggerWindow() {
     // Only one debugger instance can exist at a time right now.
     // TODO(erikkay): need an alert, dialog, something
     // or better yet, fix the one instance limitation
-    if (!DebuggerWindow::DoesDebuggerExist()) {
+    if (!DebuggerWindow::DoesDebuggerExist())
       debugger_window_ = new DebuggerWindow();
-    }
     debugger_window_->Show(current_tab);
   }
 #endif
@@ -1258,8 +1237,9 @@ void Browser::CreateNewStripWithContents(TabContents* detached_contents,
   // parent of the Find window).
   // TODO(brettw) this could probably be improved, see
   // WebContentsView::ReparentFindWindow for more.
-  if (detached_contents->AsWebContents())
-    detached_contents->AsWebContents()->view()->ReparentFindWindow(browser);
+  WebContents* web_contents = detached_contents->AsWebContents();
+  if (web_contents)
+    web_contents->view()->ReparentFindWindow(browser);
 }
 
 int Browser::GetDragActions() const {
@@ -1368,8 +1348,9 @@ void Browser::TabInsertedAt(TabContents* contents,
   // does nothing).
   // TODO(brettw) this could probably be improved, see
   // WebContentsView::ReparentFindWindow for more.
-  if (contents->AsWebContents())
-    contents->AsWebContents()->view()->ReparentFindWindow(this);
+  WebContents* web_contents = contents->AsWebContents();
+  if (web_contents)
+    web_contents->view()->ReparentFindWindow(this);
 
   // If the tab crashes in the beforeunload or unload handler, it won't be
   // able to ack. But we know we can close it.
@@ -1423,14 +1404,11 @@ void Browser::TabSelectedAt(TabContents* old_contents,
   // Propagate the profile to the location bar.
   UpdateToolbar(true);
 
-  // Force the go/stop button to change.
-  bool is_loading = new_contents->is_loading();
-  GetGoButton()->ChangeMode(is_loading ?
-      GoButton::MODE_STOP : GoButton::MODE_GO);
+  // Update stop/go state.
+  UpdateStopGoState(new_contents->is_loading());
 
   // Update commands to reflect current state.
   UpdateCommandsForTabState();
-  controller_.UpdateCommandEnabled(IDC_STOP, is_loading);
 
   // Reset the status bubble.
   GetStatusBubble()->Hide();
@@ -1683,13 +1661,7 @@ void Browser::LoadingStateChanged(TabContents* source) {
   window_->UpdateTitleBar();
 
   if (source == GetSelectedTabContents()) {
-    // Let the go button know that it should change appearance if possible.
-    bool is_loading = source->is_loading();
-    GetGoButton()->ScheduleChangeMode(is_loading ?
-        GoButton::MODE_STOP : GoButton::MODE_GO);
-
-    controller_.UpdateCommandEnabled(IDC_STOP, is_loading);
-
+    UpdateStopGoState(source->is_loading());
     GetStatusBubble()->SetStatus(GetSelectedTabContents()->GetStatusText());
   }
 }
@@ -1763,7 +1735,8 @@ bool Browser::IsApplication() const {
 }
 
 void Browser::ConvertContentsToApplication(TabContents* contents) {
-  if (!contents->AsWebContents() || !contents->AsWebContents()->web_app()) {
+  WebContents* web_contents = contents->AsWebContents();
+  if (!web_contents || !web_contents->web_app()) {
     NOTREACHED();
     return;
   }
@@ -1772,10 +1745,9 @@ void Browser::ConvertContentsToApplication(TabContents* contents) {
   if (index < 0)
     return;
 
-  WebApp* app = contents->AsWebContents()->web_app();
-  const std::wstring& app_name =
-      app->name().empty() ? ComputeApplicationNameFromURL(app->url()) :
-                            app->name();
+  WebApp* app = web_contents->web_app();
+  const std::wstring& app_name = app->name().empty() ?
+      ComputeApplicationNameFromURL(app->url()) : app->name();
   RegisterAppPrefs(app_name);
 
   tabstrip_model_.DetachTabContentsAt(index);
@@ -1882,14 +1854,10 @@ void Browser::InitCommandState() {
 
   // Navigation commands
   controller_.UpdateCommandEnabled(IDC_RELOAD, true);
-  controller_.UpdateCommandEnabled(IDC_HOME, type() == TYPE_NORMAL);
-  controller_.UpdateCommandEnabled(IDC_OPEN_CURRENT_URL, true);
-  controller_.UpdateCommandEnabled(IDC_GO, true);
 
   // Window management commands
   controller_.UpdateCommandEnabled(IDC_NEW_WINDOW, true);
   controller_.UpdateCommandEnabled(IDC_NEW_INCOGNITO_WINDOW, true);
-  controller_.UpdateCommandEnabled(IDC_PROFILE_MENU, true);
   // TODO(pkasting): Perhaps the code that populates this submenu should do
   // this?
   controller_.UpdateCommandEnabled(IDC_NEW_WINDOW_PROFILE_0, true);
@@ -1904,21 +1872,7 @@ void Browser::InitCommandState() {
   controller_.UpdateCommandEnabled(IDC_CLOSE_WINDOW, true);
   controller_.UpdateCommandEnabled(IDC_NEW_TAB, true);
   controller_.UpdateCommandEnabled(IDC_CLOSE_TAB, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_NEXT_TAB, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_PREVIOUS_TAB, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_TAB_0, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_TAB_1, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_TAB_2, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_TAB_3, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_TAB_4, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_TAB_5, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_TAB_6, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_TAB_7, true);
-  controller_.UpdateCommandEnabled(IDC_SELECT_LAST_TAB, true);
   controller_.UpdateCommandEnabled(IDC_DUPLICATE_TAB, true);
-  controller_.UpdateCommandEnabled(IDC_RESTORE_TAB,
-      (!profile_->IsOffTheRecord() && type() == TYPE_NORMAL));
-  controller_.UpdateCommandEnabled(IDC_SHOW_AS_TAB, type() == TYPE_POPUP);
   controller_.UpdateCommandEnabled(IDC_EXIT, true);
 
   // Page-related commands
@@ -1967,41 +1921,67 @@ void Browser::InitCommandState() {
   controller_.UpdateCommandEnabled(IDC_COPY_URL, true);
   controller_.UpdateCommandEnabled(IDC_PASTE, true);
 
-  // Focus various bits of UI
-  controller_.UpdateCommandEnabled(IDC_FOCUS_TOOLBAR, true);
-  controller_.UpdateCommandEnabled(IDC_FOCUS_LOCATION, true);
-  controller_.UpdateCommandEnabled(IDC_FOCUS_SEARCH, true);
-
   // Show various bits of UI
   controller_.UpdateCommandEnabled(IDC_OPEN_FILE, true);
   controller_.UpdateCommandEnabled(IDC_CREATE_SHORTCUTS, false);
-  controller_.UpdateCommandEnabled(IDC_DEVELOPER_MENU, true);
-  // The debugger doesn't work in single process mode.
-  controller_.UpdateCommandEnabled(IDC_DEBUGGER,
-      !RenderProcessHost::run_renderer_in_process());
   controller_.UpdateCommandEnabled(IDC_TASK_MANAGER, true);
   controller_.UpdateCommandEnabled(IDC_SELECT_PROFILE, true);
-  controller_.UpdateCommandEnabled(IDC_NEW_PROFILE, true);
-  controller_.UpdateCommandEnabled(IDC_REPORT_BUG, true);
-  controller_.UpdateCommandEnabled(IDC_SHOW_BOOKMARK_BAR, true);
   controller_.UpdateCommandEnabled(IDC_SHOW_HISTORY, true);
   controller_.UpdateCommandEnabled(IDC_SHOW_BOOKMARK_MANAGER, true);
   controller_.UpdateCommandEnabled(IDC_SHOW_DOWNLOADS, true);
-  controller_.UpdateCommandEnabled(IDC_CLEAR_BROWSING_DATA, true);
-  controller_.UpdateCommandEnabled(IDC_IMPORT_SETTINGS, true);
-  controller_.UpdateCommandEnabled(IDC_OPTIONS, true);
-  controller_.UpdateCommandEnabled(IDC_EDIT_SEARCH_ENGINES, true);
-  controller_.UpdateCommandEnabled(IDC_VIEW_PASSWORDS, true);
-  controller_.UpdateCommandEnabled(IDC_ABOUT, true);
   controller_.UpdateCommandEnabled(IDC_HELP_PAGE, true);
+
+  // Initialize other commands based on the window type.
+  {
+    bool normal_window = type() == TYPE_NORMAL;
+
+    // Navigation commands
+    controller_.UpdateCommandEnabled(IDC_HOME, normal_window);
+    controller_.UpdateCommandEnabled(IDC_OPEN_CURRENT_URL, normal_window);
+
+    // Window management commands
+    controller_.UpdateCommandEnabled(IDC_PROFILE_MENU, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_NEXT_TAB, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_PREVIOUS_TAB, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_TAB_0, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_TAB_1, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_TAB_2, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_TAB_3, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_TAB_4, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_TAB_5, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_TAB_6, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_TAB_7, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SELECT_LAST_TAB, normal_window);
+    controller_.UpdateCommandEnabled(IDC_RESTORE_TAB,
+        normal_window && !profile_->IsOffTheRecord());
+    controller_.UpdateCommandEnabled(IDC_SHOW_AS_TAB, (type() == TYPE_POPUP));
+
+    // Focus various bits of UI
+    controller_.UpdateCommandEnabled(IDC_FOCUS_TOOLBAR, normal_window);
+    controller_.UpdateCommandEnabled(IDC_FOCUS_LOCATION, normal_window);
+    controller_.UpdateCommandEnabled(IDC_FOCUS_SEARCH, normal_window);
+
+    // Show various bits of UI
+    controller_.UpdateCommandEnabled(IDC_DEVELOPER_MENU, normal_window);
+    controller_.UpdateCommandEnabled(IDC_DEBUGGER,
+        // The debugger doesn't work in single process mode.
+        normal_window && !RenderProcessHost::run_renderer_in_process());
+    controller_.UpdateCommandEnabled(IDC_NEW_PROFILE, normal_window);
+    controller_.UpdateCommandEnabled(IDC_REPORT_BUG, normal_window);
+    controller_.UpdateCommandEnabled(IDC_SHOW_BOOKMARK_BAR, normal_window);
+    controller_.UpdateCommandEnabled(IDC_CLEAR_BROWSING_DATA, normal_window);
+    controller_.UpdateCommandEnabled(IDC_IMPORT_SETTINGS, normal_window);
+    controller_.UpdateCommandEnabled(IDC_OPTIONS, normal_window);
+    controller_.UpdateCommandEnabled(IDC_EDIT_SEARCH_ENGINES, normal_window);
+    controller_.UpdateCommandEnabled(IDC_VIEW_PASSWORDS, normal_window);
+    controller_.UpdateCommandEnabled(IDC_ABOUT, normal_window);
+  }
 }
 
 void Browser::UpdateCommandsForTabState() {
   TabContents* current_tab = GetSelectedTabContents();
-  if (!current_tab) {
-    // It's possible for this to be null during tab restore.
+  if (!current_tab)  // May be NULL during tab restore.
     return;
-  }
 
   // Navigation commands
   NavigationController* nc = current_tab->controller();
@@ -2012,67 +1992,53 @@ void Browser::UpdateCommandsForTabState() {
   controller_.UpdateCommandEnabled(IDC_DUPLICATE_TAB,
                                    CanDuplicateContentsAt(selected_index()));
 
-  // Show various bits of UI
-  controller_.UpdateCommandEnabled(IDC_CREATE_SHORTCUTS,
-      current_tab->type() == TAB_CONTENTS_WEB &&
-      !current_tab->GetFavIcon().isNull());
+  // Initialize commands available only for web content.
+  {
+    WebContents* web_contents = current_tab->AsWebContents();
+    bool is_web_contents = web_contents != NULL;
 
-  WebContents* web_contents = current_tab->AsWebContents();
-  if (web_contents) {
     // Page-related commands
     // Only allow bookmarking for tabbed browsers.
-    controller_.UpdateCommandEnabled(IDC_STAR, type() == TYPE_NORMAL);
-    SetStarredButtonToggled(web_contents->is_starred());
+    controller_.UpdateCommandEnabled(IDC_STAR,
+        is_web_contents && (type() == TYPE_NORMAL));
+    SetStarredButtonToggled(is_web_contents && web_contents->is_starred());
     // View-source should not be enabled if already in view-source mode.
     controller_.UpdateCommandEnabled(IDC_VIEW_SOURCE,
-        current_tab->type() != TAB_CONTENTS_VIEW_SOURCE &&
+        is_web_contents && (current_tab->type() != TAB_CONTENTS_VIEW_SOURCE) &&
         current_tab->controller()->GetActiveEntry());
-    controller_.UpdateCommandEnabled(IDC_PRINT, true);
+    controller_.UpdateCommandEnabled(IDC_PRINT, is_web_contents);
     controller_.UpdateCommandEnabled(IDC_SAVE_PAGE,
-        SavePackage::IsSavableURL(current_tab->GetURL()));
+        is_web_contents && SavePackage::IsSavableURL(current_tab->GetURL()));
     controller_.UpdateCommandEnabled(IDC_ENCODING_MENU,
+        is_web_contents &&
         SavePackage::IsSavableContents(web_contents->contents_mime_type()) &&
         SavePackage::IsSavableURL(current_tab->GetURL()));
 
     // Find-in-page
-    controller_.UpdateCommandEnabled(IDC_FIND, true);
-    controller_.UpdateCommandEnabled(IDC_FIND_NEXT, true);
-    controller_.UpdateCommandEnabled(IDC_FIND_PREVIOUS, true);
-
-    // Zoom
-    controller_.UpdateCommandEnabled(IDC_ZOOM_MENU, true);
-    controller_.UpdateCommandEnabled(IDC_ZOOM_PLUS, true);
-    controller_.UpdateCommandEnabled(IDC_ZOOM_NORMAL, true);
-    controller_.UpdateCommandEnabled(IDC_ZOOM_MINUS, true);
-
-    // Show various bits of UI
-    controller_.UpdateCommandEnabled(IDC_JS_CONSOLE, true);
-  } else {
-    // Page-related commands
-    // Both disable the starring button and ensure it doesn't show a star.
-    controller_.UpdateCommandEnabled(IDC_STAR, false);
-    SetStarredButtonToggled(false);
-    controller_.UpdateCommandEnabled(IDC_VIEW_SOURCE, false);
-    controller_.UpdateCommandEnabled(IDC_PRINT, false);
-    controller_.UpdateCommandEnabled(IDC_SAVE_PAGE, false);
-    controller_.UpdateCommandEnabled(IDC_ENCODING_MENU, false);
-
-    // Find-in-page
-    controller_.UpdateCommandEnabled(IDC_FIND, false);
-    controller_.UpdateCommandEnabled(IDC_FIND_NEXT, false);
-    controller_.UpdateCommandEnabled(IDC_FIND_PREVIOUS, false);
+    controller_.UpdateCommandEnabled(IDC_FIND, is_web_contents);
+    controller_.UpdateCommandEnabled(IDC_FIND_NEXT, is_web_contents);
+    controller_.UpdateCommandEnabled(IDC_FIND_PREVIOUS, is_web_contents);
 
     // Zoom
-    controller_.UpdateCommandEnabled(IDC_ZOOM_MENU, false);
-    controller_.UpdateCommandEnabled(IDC_ZOOM_PLUS, false);
-    controller_.UpdateCommandEnabled(IDC_ZOOM_NORMAL, false);
-    controller_.UpdateCommandEnabled(IDC_ZOOM_MINUS, false);
+    controller_.UpdateCommandEnabled(IDC_ZOOM_MENU, is_web_contents);
+    controller_.UpdateCommandEnabled(IDC_ZOOM_PLUS, is_web_contents);
+    controller_.UpdateCommandEnabled(IDC_ZOOM_NORMAL, is_web_contents);
+    controller_.UpdateCommandEnabled(IDC_ZOOM_MINUS, is_web_contents);
 
     // Show various bits of UI
-    controller_.UpdateCommandEnabled(IDC_JS_CONSOLE, false);
+    controller_.UpdateCommandEnabled(IDC_JS_CONSOLE, is_web_contents);
+    controller_.UpdateCommandEnabled(IDC_CREATE_SHORTCUTS,
+        is_web_contents && !current_tab->GetFavIcon().isNull());
   }
 }
 
+void Browser::UpdateStopGoState(bool is_loading) {
+  GetGoButton()->ChangeMode(is_loading ?
+      GoButton::MODE_STOP : GoButton::MODE_GO);
+  controller_.UpdateCommandEnabled(IDC_GO, !is_loading);
+  controller_.UpdateCommandEnabled(IDC_STOP, is_loading);
+}
+
 void Browser::SetStarredButtonToggled(bool starred) {
   window_->GetStarButton()->SetToggled(starred);
 }
@@ -2340,8 +2306,8 @@ Browser* Browser::GetOrCreateTabbedBrowser() {
 void Browser::BuildPopupWindow(TabContents* source,
                                TabContents* new_contents,
                                const gfx::Rect& initial_pos) {
-  Type type = type_ == TYPE_APP ? type_ : TYPE_POPUP;
-  Browser* browser = new Browser(type, profile_);
+  Browser* browser =
+      new Browser((type_ == TYPE_APP) ? TYPE_APP : TYPE_POPUP, profile_);
   browser->set_override_bounds(initial_pos);
   browser->CreateBrowserWindow();
   // We need to Show before AddNewContents, otherwise AddNewContents will focus
diff --git a/chrome/browser/browser.h b/chrome/browser/browser.h
index 9876014..f3f2eda 100644
--- a/chrome/browser/browser.h
+++ b/chrome/browser/browser.h
@@ -128,9 +128,6 @@ class Browser : public TabStripModelDelegate,
   // Gets the title of the page in the selected tab.
   std::wstring GetCurrentPageTitle() const;
 
-  // Returns true if the current page is loading.
-  bool IsCurrentPageLoading() const;
-
   // Prepares a title string for display (removes embedded newlines, etc).
   static void FormatTitleForDisplay(std::wstring* title);
 
@@ -402,6 +399,10 @@ class Browser : public TabStripModelDelegate,
   // state.
   void UpdateCommandsForTabState();
 
+  // Set the correct stop/go icon and update the Go and Stop command states.
+  // |is_loading| is true if the current TabContents is loading.
+  void UpdateStopGoState(bool is_loading);
+
   // Change the "starred" button display to starred/unstarred.
   // TODO(evanm): migrate this to the commands framework.
   void SetStarredButtonToggled(bool starred);
diff --git a/chrome/browser/views/frame/browser_view.cc b/chrome/browser/views/frame/browser_view.cc
index f9894dd..c6ead0d 100644
--- a/chrome/browser/views/frame/browser_view.cc
+++ b/chrome/browser/views/frame/browser_view.cc
@@ -1319,7 +1319,11 @@ void BrowserView::LoadingAnimationCallback() {
     tabstrip_->UpdateLoadingAnimations();
   } else if (ShouldShowWindowIcon()) {
     // ... or in the window icon area for popups and app windows.
-    frame_->UpdateThrobber(browser_->IsCurrentPageLoading());
+    TabContents* tab_contents = browser_->GetSelectedTabContents();
+    // GetSelectedTabContents can return NULL for example under Purify when
+    // the animations are running slowly and this function is called on a timer
+    // through LoadingAnimationCallback.
+    frame_->UpdateThrobber(tab_contents && tab_contents->is_loading());
   }
 }