Oilpan: extend tracing over WebFrame trees.

Source/web/WebLocalFrameImpl.cpp

Index: Source/web/WebLocalFrameImpl.cpp
diff --git a/Source/web/WebLocalFrameImpl.cpp b/Source/web/WebLocalFrameImpl.cpp
index 31de10a9e100539a50efc577e2736c22cb9b32f3..80d40dc1f24f7c9246d33737fd844a5a0df736d9 100644
--- a/Source/web/WebLocalFrameImpl.cpp
+++ b/Source/web/WebLocalFrameImpl.cpp
@@ -1575,16 +1575,21 @@ WebLocalFrameImpl::~WebLocalFrameImpl()
     cancelPendingScopingEffort();
 }
 
+#if ENABLE(OILPAN)
 void WebLocalFrameImpl::trace(Visitor* visitor)
 {
-#if ENABLE(OILPAN)
     visitor->trace(m_frame);
     visitor->trace(m_printContext);
     visitor->trace(m_geolocationClientProxy);
+    visitor->registerWeakMembers<WebLocalFrameImpl, &WebLocalFrameImpl::clearWeakMembers>(this);
+    WebFrame::traceFrames(visitor, this);
+}
 
-    WebFrame::traceChildren(visitor, this);
-#endif
+void WebLocalFrameImpl::clearWeakMembers(Visitor* visitor)
+{
+    WebFrame::clearWeakFrames(visitor, this);
 }
+#endif
 
 void WebLocalFrameImpl::setCoreFrame(PassRefPtrWillBeRawPtr<LocalFrame> frame)
 {