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

chrome/browser/extensions/image_loading_tracker.h

Index: chrome/browser/extensions/image_loading_tracker.h
diff --git a/chrome/browser/extensions/image_loading_tracker.h b/chrome/browser/extensions/image_loading_tracker.h
index 23f7b71c463cdff49a1b6e4c7eb63656dc6fe033..c908bab594e32b01a8ce300efaf929f4393117b9 100644
--- a/chrome/browser/extensions/image_loading_tracker.h
+++ b/chrome/browser/extensions/image_loading_tracker.h
@@ -21,18 +21,22 @@ class Size;
 // Consider abstracting out a FilePathProvider (ExtensionResource) and moving
 // back to chrome/browser/ if other subsystems want to use it.
 class ImageLoadingTracker
-  : public base::RefCountedThreadSafe<ImageLoadingTracker> {
+    : public base::RefCountedThreadSafe<ImageLoadingTracker> {
  public:
   class Observer {
    public:
     // Will be called when the image with the given index has loaded.
     // The |image| is owned by the tracker, so the observer should make a copy
     // if they need to access it after this call.
-    virtual void OnImageLoaded(SkBitmap* image, size_t index) = 0;
+    virtual void OnImageLoaded(ImageLoadingTracker* source,
+                               SkBitmap* image,
+                               size_t index) = 0;
   };
 
   ImageLoadingTracker(Observer* observer, size_t image_count)
-    : observer_(observer), image_count_(image_count), posted_count_(0) {
+      : observer_(observer),
+        image_count_(image_count),
+        posted_count_(0) {
     AddRef();  // We hold on to a reference to ourself to make sure we don't
                // get deleted until we get a response from image loading (see
                // ImageLoadingDone).