Make PageScaleFactor work for oopif subframes.

content/browser/frame_host/render_frame_host_delegate.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_DELEGATE_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_DELEGATE_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 251 matching lines @@
   // CreateNewWindow.
   //
   // Note: this is not called "ShowWindow" because that will clash with
   // the Windows function which is actually a #define.
   virtual void ShowCreatedWindow(int process_id,
                                  int main_frame_widget_route_id,
                                  WindowOpenDisposition disposition,
                                  const gfx::Rect& initial_rect,
                                  bool user_gesture) {}
 
+  // Distribute page scale factor to all subframes.
+  virtual void SetPageScaleFactorForSubframes(double page_scale_factor) {}
+
  protected:
   virtual ~RenderFrameHostDelegate() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_DELEGATE_H_