MockImageResourceClient: tidy up Resource reference.

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

Index: third_party/WebKit/Source/core/fetch/MockImageResourceClient.h
diff --git a/third_party/WebKit/Source/core/fetch/MockImageResourceClient.h b/third_party/WebKit/Source/core/fetch/MockImageResourceClient.h
index e802be38d4fc1f66c667e6e2038cb6eafa55ef29..914e12691587b905f2b4b30a76dfd9b6a21dac86 100644
--- a/third_party/WebKit/Source/core/fetch/MockImageResourceClient.h
+++ b/third_party/WebKit/Source/core/fetch/MockImageResourceClient.h
@@ -32,6 +32,7 @@
 #define MockImageResourceClient_h
 
 #include "core/fetch/ImageResourceClient.h"
+#include "platform/heap/Handle.h"
 
 namespace blink {
 
@@ -58,7 +59,8 @@ public:
     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;
 };