Eliminate all UI thread decoding of extension images....

chrome/browser/gtk/browser_actions_toolbar_gtk.cc

 // Copyright (c) 2010 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/gtk/browser_actions_toolbar_gtk.h"
 
 #include <vector>
 
 #include "chrome/browser/browser.h"
 #include "chrome/browser/extensions/extension_browser_event_router.h"
@@ skipping 51 matching lines @@
 }  // namespace
 
 class BrowserActionButton : public NotificationObserver,
                             public ImageLoadingTracker::Observer,
                             public ExtensionContextMenuModel::PopupDelegate {
  public:
   BrowserActionButton(BrowserActionsToolbarGtk* toolbar,
                       Extension* extension)
       : toolbar_(toolbar),
         extension_(extension),
-        tracker_(NULL),
+        tracker_(this),
         tab_specific_icon_(NULL),
         default_icon_(NULL) {
     button_.Own(
         GtkThemeProvider::GetFrom(toolbar->profile_)->BuildChromeButton());
 
     DCHECK(extension_->browser_action());
 
     gtk_widget_set_size_request(button_.get(), kButtonSize, kButtonSize);
 
     UpdateState();
 
     // The Browser Action API does not allow the default icon path to be
     // changed at runtime, so we can load this now and cache it.
     std::string path = extension_->browser_action()->default_icon_path();
     if (!path.empty()) {
-      tracker_ = new ImageLoadingTracker(this, 1);
-      tracker_->PostLoadImageTask(extension_->GetResource(path),
+      tracker_.LoadImage(extension_->GetResource(path),
           gfx::Size(Extension::kBrowserActionIconMaxSize,
                     Extension::kBrowserActionIconMaxSize));
     }
 
     g_signal_connect(button_.get(), "button-press-event",
                      G_CALLBACK(OnButtonPress), this);
     g_signal_connect(button_.get(), "clicked",
                      G_CALLBACK(OnClicked), this);
     g_signal_connect_after(button_.get(), "expose-event",
                            G_CALLBACK(OnExposeEvent), this);
     g_signal_connect(button_.get(), "drag-begin",
                      G_CALLBACK(&OnDragBegin), this);
 
     registrar_.Add(this, NotificationType::EXTENSION_BROWSER_ACTION_UPDATED,
                    Source<ExtensionAction>(extension->browser_action()));
   }
 
   ~BrowserActionButton() {
     if (tab_specific_icon_)
       g_object_unref(tab_specific_icon_);
 
     if (default_icon_)
       g_object_unref(default_icon_);
 
     button_.Destroy();
-
-    if (tracker_)
-      tracker_->StopTrackingImageLoad();
   }
 
   GtkWidget* widget() { return button_.get(); }
 
   Extension* extension() { return extension_; }
 
   // NotificationObserver implementation.
   void Observe(NotificationType type,
                const NotificationSource& source,
                const NotificationDetails& details) {
     if (type == NotificationType::EXTENSION_BROWSER_ACTION_UPDATED)
       UpdateState();
     else
       NOTREACHED();
   }
 
   // ImageLoadingTracker::Observer implementation.
-  void OnImageLoaded(SkBitmap* image, size_t index) {
+  void OnImageLoaded(SkBitmap* image, ExtensionResource resource, int index) {
     if (image) {
       default_skbitmap_ = *image;
       default_icon_ = gfx::GdkPixbufFromSkBitmap(image);
     }
-    tracker_ = NULL;  // The tracker object will delete itself when we return.
     UpdateState();
   }
 
   // Updates the button based on the latest state from the associated
   // browser action.
   void UpdateState() {
     int tab_id = toolbar_->GetCurrentTabId();
     if (tab_id < 0)
       return;
 
@@ skipping 116 matching lines @@
   // The toolbar containing this button.
   BrowserActionsToolbarGtk* toolbar_;
 
   // The extension that contains this browser action.
   Extension* extension_;
 
   // The gtk widget for this browser action.
   OwnedWidgetGtk button_;
 
   // Loads the button's icons for us on the file thread.
-  ImageLoadingTracker* tracker_;
+  ImageLoadingTracker tracker_;
 
   // If we are displaying a tab-specific icon, it will be here.
   GdkPixbuf* tab_specific_icon_;
 
   // If the browser action has a default icon, it will be here.
   GdkPixbuf* default_icon_;
 
   // Same as |default_icon_|, but stored as SkBitmap.
   SkBitmap default_skbitmap_;
 
@@ skipping 349 matching lines @@
 gboolean BrowserActionsToolbarGtk::OnDragFailed(GtkWidget* widget,
                                                 GdkDragContext* drag_context,
                                                 GtkDragResult result) {
   // We connect to this signal and return TRUE so that the default failure
   // animation (wherein the drag widget floats back to the start of the drag)
   // does not show, and the drag-end signal is emitted immediately instead of
   // several seconds later.
   return TRUE;
 }
 
-void BrowserActionsToolbarGtk::OnHierarchyChanged(GtkWidget* widget,
-                                                  GtkWidget* previous_toplevel) {
+void BrowserActionsToolbarGtk::OnHierarchyChanged(
+    GtkWidget* widget, GtkWidget* previous_toplevel) {
   GtkWidget* toplevel = gtk_widget_get_toplevel(widget);
   if (!GTK_WIDGET_TOPLEVEL(toplevel))
     return;
 
   g_signal_connect(toplevel, "set-focus", G_CALLBACK(OnSetFocusThunk), this);
 }
 
 void BrowserActionsToolbarGtk::OnSetFocus(GtkWidget* widget,
                                           GtkWidget* focus_widget) {
   ExtensionPopupGtk* popup = ExtensionPopupGtk::get_current_extension_popup();
@@ skipping 98 matching lines @@
 
     // TODO(estade): set the menu item's tooltip.
   }
 
   gtk_chrome_button_set_paint_state(GTK_CHROME_BUTTON(overflow),
                                     GTK_STATE_ACTIVE);
   overflow_menu_->PopupAsFromKeyEvent(overflow);
 
   return FALSE;
 }