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

content/browser/renderer_host/render_widget_host_delegate.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_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_DELEGATE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_DELEGATE_H_
 
 #include <stdint.h>
 
 #include <vector>
 
 #include "build/build_config.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebDisplayMode.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/gfx/native_widget_types.h"
 
 namespace blink {
 class WebMouseWheelEvent;
 class WebGestureEvent;
+struct WebScreenInfo;
 }
 
 namespace gfx {
 class Point;
 class Rect;
 class Size;
 }
 
 namespace content {
 
@@ skipping 23 matching lines @@
   virtual void RenderWidgetWasResized(RenderWidgetHostImpl* render_widget_host,
                                       bool width_changed) {}
 
   // The contents auto-resized and the container should match it.
   virtual void ResizeDueToAutoResize(RenderWidgetHostImpl* render_widget_host,
                                      const gfx::Size& new_size) {}
 
   // The screen info has changed.
   virtual void ScreenInfoChanged() {}
 
+  // Sets the device scale factor for frames associated with this WebContents.
+  virtual void UpdateDeviceScaleFactor(double device_scale_factor) {}
+
+  // Retrieve screen information.
+  virtual void GetScreenInfo(blink::WebScreenInfo* web_screen_info);
+
   // Callback to give the browser a chance to handle the specified keyboard
   // event before sending it to the renderer.
   // Returns true if the |event| was handled. Otherwise, if the |event| would
   // be handled in HandleKeyboardEvent() method as a normal keyboard shortcut,
   // |*is_keyboard_shortcut| should be set to true.
   virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
                                       bool* is_keyboard_shortcut);
 
   // Callback to inform the browser that the renderer did not process the
   // specified events. This gives an opportunity to the browser to process the
@@ skipping 141 matching lines @@
   // this RenderWidgetHost.
   virtual bool IsHidden();
 
  protected:
   virtual ~RenderWidgetHostDelegate() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_DELEGATE_H_