Send initializeChildFrame from RenderFrameProxy instead of WebLocalFrame

public/web/WebRemoteFrameClient.h

Index: public/web/WebRemoteFrameClient.h
diff --git a/public/web/WebRemoteFrameClient.h b/public/web/WebRemoteFrameClient.h
index 06ef91fc9f7dbf98bf00774aa407e825ff83208f..febd991fd0443fb147e28d2a012e84991429354b 100644
--- a/public/web/WebRemoteFrameClient.h
+++ b/public/web/WebRemoteFrameClient.h
@@ -19,7 +19,13 @@ public:
         WebLocalFrame* sourceFrame,
         WebRemoteFrame* targetFrame,
         WebSecurityOrigin targetOrigin,
-        WebDOMMessageEvent) = 0;
+        WebDOMMessageEvent) { }
+
+    // Send initial drawing parameters to a child frame that is being rendered
+    // out of process.
+    virtual void initializeChildFrame(
+        const WebRect& frameRect,
+        float scaleFactor) { }
 };
 
 } // namespace blink