Add a simpler key type for scratch resource keys.

include/gpu/GrGpuResource.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 GrGpuResource_DEFINED
 #define GrGpuResource_DEFINED
 
@@ skipping 210 matching lines @@
     /**
      * This entry point should be called whenever gpuMemorySize() should report a different size.
      * The cache will call gpuMemorySize() to update the current size of the resource.
      */
     void didChangeGpuMemorySize() const;
 
     /**
      * Optionally called by the GrGpuResource subclass if the resource can be used as scratch.
      * By default resources are not usable as scratch. This should only be called once.
      **/
-    void setScratchKey(const GrResourceKey& scratchKey);
+    void setScratchKey(const GrScratchKey& scratchKey);
 
 private:
     /**
      * Frees the object in the underlying 3D API. Called by CacheAccess.
      */
     void release();
 
     virtual size_t onGpuMemorySize() const = 0;
 
     // See comments in CacheAccess.
@@ skipping 25 matching lines @@
          * implies that kBudgeted_Flag is not set.
          */
         kWrapped_Flag       = 0x2,
 
         /**
          * If set then fContentKey is valid and the resource is cached based on its content.
          */
         kContentKeySet_Flag = 0x4,
     };
 
-    // TODO(bsalomon): Remove GrResourceKey and use different simpler types for content and scratch
-    // keys.
-    GrResourceKey           fScratchKey;
+    GrScratchKey            fScratchKey;
+    // TODO(bsalomon): Remove GrResourceKey and use different simpler type for content keys.
     GrResourceKey           fContentKey;
 
     // This is not ref'ed but abandon() or release() will be called before the GrGpu object
     // is destroyed. Those calls set will this to NULL.
     GrGpu*                  fGpu;
     mutable size_t          fGpuMemorySize;
 
     uint32_t                fFlags;
     const uint32_t          fUniqueID;
 
     SkAutoTUnref<const SkData> fData;
 
     typedef GrIORef<GrGpuResource> INHERITED;
     friend class GrIORef<GrGpuResource>; // to access notifyIsPurgable.
 };
 
 #endif