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

chrome/browser/gtk/location_bar_view_gtk.cc

Index: chrome/browser/gtk/location_bar_view_gtk.cc
===================================================================
--- chrome/browser/gtk/location_bar_view_gtk.cc	(revision 42362)
+++ chrome/browser/gtk/location_bar_view_gtk.cc	(working copy)
@@ -1057,6 +1057,7 @@
       profile_(profile),
       page_action_(page_action),
       last_icon_pixbuf_(NULL),
+      tracker_(this),
       preview_enabled_(false) {
   event_box_.Own(gtk_event_box_new());
   gtk_widget_set_size_request(event_box_.get(),
@@ -1083,10 +1084,9 @@
   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(
+    tracker_.PostLoadImageTask(
         extension->GetResource(*iter),
         gfx::Size(Extension::kPageActionIconMaxSize,
                   Extension::kPageActionIconMaxSize));
@@ -1094,8 +1094,6 @@
 }
 
 LocationBarViewGtk::PageActionViewGtk::~PageActionViewGtk() {
-  if (tracker_)
-    tracker_->StopTrackingImageLoad();
   image_.Destroy();
   event_box_.Destroy();
   for (PixbufMap::iterator iter = pixbufs_.begin(); iter != pixbufs_.end();
@@ -1178,11 +1176,11 @@
   }
 }
 
-void LocationBarViewGtk::PageActionViewGtk::OnImageLoaded(SkBitmap* image,
-                                                          size_t index) {
+void LocationBarViewGtk::PageActionViewGtk::OnImageLoaded(
+    SkBitmap* image, int index) {
   // We loaded icons()->size() icons, plus one extra if the page action had
   // a default icon.
-  size_t 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(index < total_icons);
@@ -1197,10 +1195,6 @@
       pixbufs_[page_action_->default_icon_path()] = pixbuf;
   }
 
-  // If we are done, release the tracker.
-  if (index == (total_icons - 1))
-    tracker_ = NULL;
-
   owner_->UpdatePageActions();
 }