Make GrCacheable implement its own ref counting.

include/gpu/GrContext.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrContext_DEFINED
 #define GrContext_DEFINED
 
@@ skipping 1101 matching lines @@
         if (NULL == fTexture) {
             return NULL;
         }
         GrTexture* texture = fTexture;
         fTexture = NULL;
 
         // This GrAutoScratchTexture has a ref from lockAndRefScratchTexture, which we give up now.
         // The cache also has a ref which we are lending to the caller of detach(). When the caller
         // lets go of the ref and the ref count goes to 0 internal_dispose will see this flag is
         // set and re-ref the texture, thereby restoring the cache's ref.
-        SkASSERT(texture->getRefCnt() > 1);
+        SkASSERT(!texture->unique());
         texture->impl()->setFlag((GrTextureFlags) GrTextureImpl::kReturnToCache_FlagBit);
         texture->unref();
         SkASSERT(NULL != texture->getCacheEntry());
 
         return texture;
     }
 
     GrTexture* set(GrContext* context,
                    const GrTextureDesc& desc,
                    GrContext::ScratchTexMatch match = GrContext::kApprox_ScratchTexMatch) {
@@ skipping 12 matching lines @@
     }
 
     GrTexture* texture() { return fTexture; }
 
 private:
     GrContext*                    fContext;
     GrTexture*                    fTexture;
 };
 
 #endif