Handle the case when the GrResourceCache timestamp wraps.

src/gpu/GrResourceCache.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 GrResourceCache_DEFINED
 #define GrResourceCache_DEFINED
@@ skipping 153 matching lines @@
      */
     void setOverBudgetCallback(PFOverBudgetCB overBudgetCB, void* data) {
         fOverBudgetCB = overBudgetCB;
         fOverBudgetData = data;
     }
 
 #if GR_GPU_STATS
     void dumpStats(SkString*) const;
 #endif
 
+    // This function is for unit testing and is only defined in test tools.
+    void changeTimestamp(uint32_t newTimestamp);
+
 private:
     ///////////////////////////////////////////////////////////////////////////
     /// @name Methods accessible via ResourceAccess
     ////
     void insertResource(GrGpuResource*);
     void removeResource(GrGpuResource*);
     void notifyPurgeable(GrGpuResource*);
     void didChangeGpuMemorySize(const GrGpuResource*, size_t oldSize);
     void changeUniqueKey(GrGpuResource*, const GrUniqueKey&);
     void removeUniqueKey(GrGpuResource*);
     void willRemoveScratchKey(const GrGpuResource*);
     void didChangeBudgetStatus(GrGpuResource*);
     void refAndMakeResourceMRU(GrGpuResource*);
     /// @}
 
     void internalPurgeAsNeeded();
     void processInvalidUniqueKeys(const SkTArray<GrUniqueKeyInvalidatedMessage>&);
     void addToNonpurgeableArray(GrGpuResource*);
     void removeFromNonpurgeableArray(GrGpuResource*);
     bool overBudget() const { return fBudgetedBytes > fMaxBytes || fBudgetedCount > fMaxCount; }
 
+    uint32_t getNextTimestamp();
+
 #ifdef SK_DEBUG
     bool isInCache(const GrGpuResource* r) const;
     void validate() const;
 #else
     void validate() const {}
 #endif
 
     class AutoValidate;
 
     class AvailableForScratchUse;
@@ skipping 123 matching lines @@
 
     friend class GrGpuResource; // To access all the proxy inline methods.
     friend class GrResourceCache; // To create this type.
 };
 
 inline GrResourceCache::ResourceAccess GrResourceCache::resourceAccess() {
     return ResourceAccess(this);
 }
 
 #endif