MockImageResourceClient: tidy up Resource reference.

third_party/WebKit/Source/core/fetch/MockImageResourceClient.h

 /*
  * Copyright (c) 2013, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef MockImageResourceClient_h
 #define MockImageResourceClient_h
 
 #include "core/fetch/ImageResourceClient.h"
+#include "platform/heap/Handle.h"
 
 namespace blink {
 
 template<typename T> class ResourcePtr;
 
 class Resource;
 
 class MockImageResourceClient final : public ImageResourceClient {
 public:
     explicit MockImageResourceClient(const ResourcePtr<Resource>&);
     ~MockImageResourceClient() override;
 
     void imageChanged(ImageResource*, const IntRect*) override
     {
         m_imageChangedCount++;
     }
 
     void notifyFinished(Resource*) override;
     String debugName() const override { return "MockImageResourceClient"; }
 
     int imageChangedCount() const { return m_imageChangedCount; }
     bool notifyFinishedCalled() const { return m_notifyFinishedCalled; }
 
     void removeAsClient();
 
 private:
-    Resource* m_resource;
+    // TODO(Oilpan): properly trace when ImageResourceClient is on the heap.
+    RawPtrWillBeUntracedMember<Resource> m_resource;
     int m_imageChangedCount;
     bool m_notifyFinishedCalled;
 };
 
 } // namespace blink
 
 #endif // MockImageResourceClient_h