only notify bitmaps that have been added to the cache

src/core/SkBitmapCache.h

Index: src/core/SkBitmapCache.h
diff --git a/src/core/SkBitmapCache.h b/src/core/SkBitmapCache.h
index c54f96141c18b2dd3b979a369322494cb5d9b518..de50aabe1e4d7eb28e0cd1149a6cdd4d724fcdba 100644
--- a/src/core/SkBitmapCache.h
+++ b/src/core/SkBitmapCache.h
@@ -50,7 +50,7 @@ public:
      * The width and the height of the provided subset must be the same as the result bitmap ones.
      * result must be marked isImmutable()
      */
-    static bool Add(uint32_t genID, const SkIRect& subset, const SkBitmap& result,
+    static bool Add(SkPixelRef*, const SkIRect& subset, const SkBitmap& result,
                     SkResourceCache* localCache = NULL);
 };