Cross-process frames should be notified of device scale factor changes.

content/renderer/render_widget.h

 // Copyright (c) 2012 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_RENDERER_RENDER_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 481 matching lines @@
 
   // Called by the browser process to update text input state.
   void OnRequestTextInputStateUpdate();
 #endif
 
   // Notify the compositor about a change in viewport size. This should be
   // used only with auto resize mode WebWidgets, as normal WebWidgets should
   // go through OnResize.
   void AutoResizeCompositor();
 
-  virtual void SetDeviceScaleFactor(float device_scale_factor);
+  virtual void OnSetDeviceScaleFactor(float device_scale_factor);
   bool SetDeviceColorProfile(const std::vector<char>& color_profile);
 
   virtual void OnOrientationChange();
 
   // Override points to notify derived classes that a paint has happened.
   // DidInitiatePaint happens when that has completed, and subsequent rendering
   // won't affect the painted content. DidFlushPaint happens once we've received
   // the ACK that the screen has been updated. For a given paint operation,
   // these overrides will always be called in the order DidInitiatePaint,
   // DidFlushPaint.
@@ skipping 270 matching lines @@
   // This reference is set by the RenderFrame and is used to query the IME-
   // related state from the plugin to later send to the browser.
   PepperPluginInstanceImpl* focused_pepper_plugin_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_