Revert of Use the GrCacheable ID to eliminate the need for notifications to GrGpuGL when textures and RTs are…

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; }
 
     /**
      * Gets an id that is unique for this GrCacheable object. It is static in that it does
      * not change when the content of the GrCacheable object changes. This will never return
      * 0.
      */
-    uint64_t getInstanceID() const { return fInstanceID; }
+    uint32_t getGenerationID() const;
 
 protected:
     GrCacheable()
         : fCacheEntry(NULL)
-        , fInstanceID(CreateInstanceID()) {}
+        , fGenID(0) {}
 
     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:
-    static uint64_t CreateInstanceID();
-
     GrResourceCacheEntry*   fCacheEntry;  // NULL if not in cache
-    mutable uint64_t        fInstanceID;
+    mutable uint32_t        fGenID;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif