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

chrome/browser/cocoa/extensions/browser_action_button.mm

Index: chrome/browser/cocoa/extensions/browser_action_button.mm
diff --git a/chrome/browser/cocoa/extensions/browser_action_button.mm b/chrome/browser/cocoa/extensions/browser_action_button.mm
index c21b76fdaafab04d8eadd7cf04640ac83b86fcd2..df372841e94dfc6baf9e225c319679498f4748cf 100644
--- a/chrome/browser/cocoa/extensions/browser_action_button.mm
+++ b/chrome/browser/cocoa/extensions/browser_action_button.mm
@@ -55,7 +55,8 @@ class ExtensionImageTrackerBridge : public NotificationObserver,
   }
 
   // ImageLoadingTracker::Observer implementation.
-  void OnImageLoaded(SkBitmap* image, size_t index) {
+  void OnImageLoaded(ImageLoadingTracker* source, SkBitmap* image,
+                     size_t index) {
     if (image)
       [owner_ setDefaultIcon:gfx::SkBitmapToNSImage(*image)];
     tracker_ = NULL;