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

ui/aura/window_tree_host.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 UI_AURA_WINDOW_TREE_HOST_H_
 #define UI_AURA_WINDOW_TREE_HOST_H_
 
 #include <vector>
 
 #include "base/event_types.h"
@@ skipping 161 matching lines @@
   // Gets/Sets the size of the WindowTreeHost (in pixels).
   virtual gfx::Rect GetBounds() const = 0;
   virtual void SetBounds(const gfx::Rect& bounds_in_pixels) = 0;
 
   // Sets the OS capture to the root window.
   virtual void SetCapture() = 0;
 
   // Releases OS capture of the root window.
   virtual void ReleaseCapture() = 0;
 
+  // For testing : WJM

[Charlie Reis, 2016/08/10 00:07:12]

WJM?

[wjmaclean, 2016/08/10 15:54:26]

Done.

The comment was designed to make sure I didn't leave this in ... thanks for
spotting.

+  void OnHostResized(const gfx::Size& new_size);
+
  protected:
   friend class TestScreen;  // TODO(beng): see if we can remove/consolidate.
 
   WindowTreeHost();
   void DestroyCompositor();
   void DestroyDispatcher();
 
   void CreateCompositor();
   void OnAcceleratedWidgetAvailable();
 
   // Returns the location of the RootWindow on native screen.
   virtual gfx::Point GetLocationOnNativeScreen() const = 0;
 
   void OnHostMoved(const gfx::Point& new_location);
-  void OnHostResized(const gfx::Size& new_size);
   void OnHostWorkspaceChanged();
   void OnHostCloseRequested();
   void OnHostActivated();
   void OnHostLostWindowCapture();
 
   // Sets the currently displayed cursor.
   virtual void SetCursorNative(gfx::NativeCursor cursor) = 0;
 
   // Moves the cursor to the specified location relative to the root window.
   virtual void MoveCursorToNative(const gfx::Point& location) = 0;
@@ skipping 45 matching lines @@
   bool owned_input_method_;
 
   gfx::Insets output_surface_padding_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHost);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_TREE_HOST_H_