Adds the source ImageLoadingTracker to OnImageLoaded. I need this in a

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 671 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(
+    ImageLoadingTracker* source, SkBitmap* image, size_t 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();
   if (!page_action_->default_icon_path().empty())
     total_icons++;
   DCHECK(static_cast<int>(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) {
@@ skipping 247 matching lines @@
       ++result;
   }
   return result;
 }
 
 void LocationBarViewMac::PageActionViewList::OnMousePressed(NSRect iconFrame,
                                                             size_t index) {
   ViewAt(index)->OnMousePressed(iconFrame);
 }