Add size change notifications to GrResourceCache

include/gpu/GrCacheable.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrCacheable_DEFINED
 #define GrCacheable_DEFINED
 
@@ skipping 28 matching lines @@
     virtual bool isValidOnGpu() const = 0;
 
     void setCacheEntry(GrResourceCacheEntry* cacheEntry) { fCacheEntry = cacheEntry; }
     GrResourceCacheEntry* getCacheEntry() { return fCacheEntry; }
 
 protected:
     GrCacheable() : fCacheEntry(NULL) {}
 
     bool isInCache() const { return NULL != fCacheEntry; }
 
+    /**
+     * This entry point should be called whenever gpuMemorySize() begins
+     * reporting a different size. If the object is in the cache, it will call
+     * gpuMemorySize() immediately and pass the new size on to the resource
+     * cache.
+     */
+    void didChangeGpuMemorySize() const;
+
 private:
     GrResourceCacheEntry* fCacheEntry;  // NULL if not in cache
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif