Add support for creating texture backed images where Skia will delete the texture.

src/gpu/GrGpuResourceCacheAccess.h

Index: src/gpu/GrGpuResourceCacheAccess.h
diff --git a/src/gpu/GrGpuResourceCacheAccess.h b/src/gpu/GrGpuResourceCacheAccess.h
index 4f38fc600212a5d483751f3b7374497cffc17b68..f86850eea2a08c6bf4cbd167e523321037bdc382 100644
--- a/src/gpu/GrGpuResourceCacheAccess.h
+++ b/src/gpu/GrGpuResourceCacheAccess.h
@@ -33,7 +33,7 @@ private:
     /**
      * Is the resource object wrapping an externally allocated GPU resource?
      */
-    bool isWrapped() const { return GrGpuResource::kWrapped_LifeCycle == fResource->fLifeCycle; }
+    bool isExternal() const { return fResource->isExternal(); }
  
     /**
      * Called by the cache to delete the resource under normal circumstances.