Make GrResourceCache2 responsible for calling release, abandon, and ~.

src/gpu/GrResourceCache2.h

Index: src/gpu/GrResourceCache2.h
diff --git a/src/gpu/GrResourceCache2.h b/src/gpu/GrResourceCache2.h
index 8b4d1d0e67564142ba05eb724c3ed7c001c6241d..805d359eb4e0061f9a7177ec2b759b5f426959e2 100644
--- a/src/gpu/GrResourceCache2.h
+++ b/src/gpu/GrResourceCache2.h
@@ -148,7 +148,7 @@ private:
     ////
     void insertResource(GrGpuResource*);
     void removeResource(GrGpuResource*);
-    void notifyPurgable(const GrGpuResource*);
+    void notifyPurgable(GrGpuResource*);
     void didChangeGpuMemorySize(const GrGpuResource*, size_t oldSize);
     bool didSetContentKey(GrGpuResource*);
     void makeResourceMRU(GrGpuResource*);
@@ -241,7 +241,7 @@ private:
     /**
      * Called by GrGpuResources when they detects that they are newly purgable.
      */
-    void notifyPurgable(const GrGpuResource* resource) { fCache->notifyPurgable(resource); }
+    void notifyPurgable(GrGpuResource* resource) { fCache->notifyPurgable(resource); }
 
     /**
      * Called by GrGpuResources when their sizes change.