Add a simpler key type for scratch resource keys.

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 20 matching lines @@
     /**
      * Changes whether the resource counts against the resource cache budget.
      */
     void setBudgeted(bool countsAgainstBudget) { fResource->setBudgeted(countsAgainstBudget); }
 
     /**
      * Is the resource currently cached as scratch? This means it has a valid scratch key and does
      * not have a content key.
      */
     bool isScratch() const {
-        SkASSERT(fResource->fScratchKey.isScratch());
-        return NULL == this->getContentKey() && !fResource->fScratchKey.isNullScratch();
+        return NULL == this->getContentKey() && fResource->fScratchKey.isValid();
     }
 
     /** 
      * 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().
+     * used as a content resource rather than scratch. Check isScratch().
      */
-    const GrResourceKey& getScratchKey() const { return fResource->fScratchKey; }
+    const GrScratchKey& 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.
      */
@@ skipping 52 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