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

chrome/browser/cocoa/location_bar_view_mac.mm

 // 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.
 
 #import "chrome/browser/cocoa/location_bar_view_mac.h"
 
 #include "app/l10n_util_mac.h"
 #include "app/resource_bundle.h"
 #include "base/i18n/rtl.h"
 #include "base/nsimage_cache_mac.h"
@@ skipping 612 matching lines @@
   Extension* extension = profile->GetExtensionsService()->GetExtensionById(
       page_action->extension_id(), false);
   DCHECK(extension);
 
   // Load all the icons declared in the manifest. This is the contents of the
   // icons array, plus the default_icon property, if any.
   std::vector<std::string> icon_paths(*page_action->icon_paths());
   if (!page_action_->default_icon_path().empty())
     icon_paths.push_back(page_action_->default_icon_path());
 
-  tracker_ = new ImageLoadingTracker(this, icon_paths.size());
   for (std::vector<std::string>::iterator iter = icon_paths.begin();
        iter != icon_paths.end(); ++iter) {
-    tracker_->PostLoadImageTask(extension->GetResource(*iter),
-                                gfx::Size(Extension::kPageActionIconMaxSize,
-                                          Extension::kPageActionIconMaxSize));
+    tracker_.PostLoadImageTask(extension->GetResource(*iter),
+                               gfx::Size(Extension::kPageActionIconMaxSize,
+                                         Extension::kPageActionIconMaxSize));
   }
 
   registrar_.Add(this, NotificationType::EXTENSION_HOST_VIEW_SHOULD_CLOSE,
       Source<Profile>(profile_));
 }
 
 LocationBarViewMac::PageActionImageView::~PageActionImageView() {
-  if (tracker_)
-    tracker_->StopTrackingImageLoad();
 }
 
 NSSize LocationBarViewMac::PageActionImageView::GetPreferredImageSize() {
   NSImage* image = GetImage();
   if (image) {
     return [image size];
   } else {
     return NSMakeSize(Extension::kPageActionIconMaxSize,
                       Extension::kPageActionIconMaxSize);
   }
@@ skipping 24 matching lines @@
                            anchoredAt:arrowPoint
                         arrowLocation:kTopRight];
   } else {
     ExtensionBrowserEventRouter::GetInstance()->PageActionExecuted(
         profile_, page_action_->extension_id(), page_action_->id(),
         current_tab_id_, current_url_.spec(),
         1);
   }
 }
 
-void LocationBarViewMac::PageActionImageView::OnImageLoaded(SkBitmap* image,
-                                                            size_t index) {
+void LocationBarViewMac::PageActionImageView::OnImageLoaded(
+    SkBitmap* image, int index) {
   // We loaded icons()->size() icons, plus one extra if the Page Action had
   // a default icon.
-  int total_icons = page_action_->icon_paths()->size();
+  int total_icons = static_cast<int>(page_action_->icon_paths()->size());
   if (!page_action_->default_icon_path().empty())
     total_icons++;
-  DCHECK(static_cast<int>(index) < total_icons);
+  DCHECK(index < total_icons);
 
   // Map the index of the loaded image back to its name. If we ever get an
   // index greater than the number of icons, it must be the default icon.
   if (image) {
-    if (index < page_action_->icon_paths()->size())
+    if (index < total_icons)
       page_action_icons_[page_action_->icon_paths()->at(index)] = *image;
     else
       page_action_icons_[page_action_->default_icon_path()] = *image;
   }
 
-  // If we are done, release the tracker.
-  if (static_cast<int>(index) == (total_icons - 1))
-    tracker_ = NULL;
-
   owner_->UpdatePageActions();
 
   if (preview_enabled_)
     [owner_->GetAutocompleteTextField() display];
 }
 
 void LocationBarViewMac::PageActionImageView::UpdateVisibility(
     TabContents* contents, const GURL& url) {
   // Save this off so we can pass it back to the extension when the action gets
   // executed. See PageActionImageView::OnMousePressed.
@@ skipping 227 matching lines @@
       ++result;
   }
   return result;
 }
 
 void LocationBarViewMac::PageActionViewList::OnMousePressed(NSRect iconFrame,
                                                             size_t index) {
   ViewAt(index)->OnMousePressed(iconFrame);
 }