Use scratch keys for stencil buffers.

src/gpu/GrGpuResourceCacheAccess.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 GrGpuResourceCacheAccess_DEFINED
 #define GrGpuResourceCacheAccess_DEFINED
@@ skipping 32 matching lines @@
     }
 
     /** 
      * If this resource can be used as a scratch resource this returns a valid scratch key.
      * Otherwise it returns a key for which isNullScratch is true. The resource may currently be
      * used as content resource rather than scratch. Check isScratch().
      */
     const GrResourceKey& getScratchKey() const { return fResource->fScratchKey; }
 
     /**
+     * If the resource has a scratch key, the key will be removed. Since scratch keys are installed
+     * at resource creation time, this means the resource will never again be used as scratch.
+     */
+    void removeScratchKey() const { fResource->removeScratchKey();  }
+
+    /**
      * If the resource is currently cached by a content key, the key is returned, otherwise NULL.
      */
     const GrResourceKey* getContentKey() const {
         if (fResource->fFlags & GrGpuResource::kContentKeySet_Flag) {
             return &fResource->fContentKey;
         }
         return NULL;
     }
 
     /**
@@ skipping 44 matching lines @@
     friend class GrGpuResource; // to construct/copy this type.
 };
 
 inline GrGpuResource::CacheAccess GrGpuResource::cacheAccess() { return CacheAccess(this); }
 
 inline const GrGpuResource::CacheAccess GrGpuResource::cacheAccess() const {
     return CacheAccess(const_cast<GrGpuResource*>(this));
 }
 
 #endif