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

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index ad392c731c1dd6f47bbd0f0bee194edcca4133b8..be8827f829151484ace031d304778ddfb6cf405b 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -594,6 +594,8 @@ class CONTENT_EXPORT WebContentsImpl
   void ResizeDueToAutoResize(RenderWidgetHostImpl* render_widget_host,
                              const gfx::Size& new_size) override;
   void ScreenInfoChanged() override;
+  void UpdateDeviceScaleFactor(double device_scale_factor) override;
+  double DefaultDeviceScaleFactor() override;
   bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
                               bool* is_keyboard_shortcut) override;
   void HandleKeyboardEvent(const NativeWebKeyboardEvent& event) override;
@@ -634,6 +636,7 @@ class CONTENT_EXPORT WebContentsImpl
   void OnFirstPaintAfterLoad(RenderWidgetHostImpl* render_widget_host) override;
   TextInputManager* GetTextInputManager() override;
 
+
   // RenderFrameHostManager::Delegate ------------------------------------------
 
   bool CreateRenderViewForRenderManager(