Set correct viewport size for an out of process iframe.

content/browser/frame_host/cross_process_frame_connector.h

Index: content/browser/frame_host/cross_process_frame_connector.h
diff --git a/content/browser/frame_host/cross_process_frame_connector.h b/content/browser/frame_host/cross_process_frame_connector.h
index 61103f670180bd2f56dd05007496cd959e41b890..4a940879f4c42c46d2b0289f04c7629d9608f8c5 100644
--- a/content/browser/frame_host/cross_process_frame_connector.h
+++ b/content/browser/frame_host/cross_process_frame_connector.h
@@ -99,6 +99,7 @@ class CrossProcessFrameConnector {
   void OnReclaimCompositorResources(
       const FrameHostMsg_ReclaimCompositorResources_Params& params);
   void OnForwardInputEvent(const blink::WebInputEvent* event);
+  void OnInitializeChildFrame(gfx::Rect frame_rect, float scale_factor);
 
   // The RenderFrameHost that routes messages to the parent frame's renderer
   // process.
@@ -110,6 +111,7 @@ class CrossProcessFrameConnector {
   RenderWidgetHostViewChildFrame* view_;
 
   gfx::Rect child_frame_rect_;
+  float device_scale_factor_;
 };
 
 }  // namespace content