Make GrResourceCache use a priority queue of purgeable resources.

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 37 matching lines @@
     /**
      * Called by the cache to delete the resource when the backend 3D context is no longer valid.
      */
     void abandon() {
         fResource->abandon();
         if (fResource->isPurgeable()) {            
             SkDELETE(fResource);
         }
     }
 
+    uint32_t timestamp() const { return fResource->fTimestamp; }
+    void setTimestamp(uint32_t ts) { fResource->fTimestamp = ts; }
+
+    int* accessCacheIndex() const { return &fResource->fCacheArrayIndex; }
+
     CacheAccess(GrGpuResource* resource) : fResource(resource) {}
     CacheAccess(const CacheAccess& that) : fResource(that.fResource) {}
     CacheAccess& operator=(const CacheAccess&); // unimpl
 
     // No taking addresses of this type.
     const CacheAccess* operator&() const;
     CacheAccess* operator&();
 
     GrGpuResource* fResource;
 
     friend class GrGpuResource; // to construct/copy this type.
     friend class GrResourceCache; // to use this type
     friend void test_unbudgeted_to_scratch(skiatest::Reporter* reporter); // for unit testing
 };
 
 inline GrGpuResource::CacheAccess GrGpuResource::cacheAccess() { return CacheAccess(this); }
 
 inline const GrGpuResource::CacheAccess GrGpuResource::cacheAccess() const {
     return CacheAccess(const_cast<GrGpuResource*>(this));
 }
 
 #endif