aura: Remove WindowTreeHost::OnDeviceScaleFactorChanged.

mojo/aura/window_tree_host_mojo.cc

 // Copyright 2014 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.
 
 #include "mojo/aura/window_tree_host_mojo.h"
 
 #include <vector>
 
 #include "mojo/aura/window_tree_host_mojo_delegate.h"
 #include "ui/aura/env.h"
@@ skipping 119 matching lines @@
 
 void WindowTreeHostMojo::ReleaseCapture() {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostMojo::PostNativeEvent(
     const base::NativeEvent& native_event) {
   NOTIMPLEMENTED();
 }
 
-void WindowTreeHostMojo::OnDeviceScaleFactorChanged(
-    float device_scale_factor) {
-  NOTIMPLEMENTED();
-}
-
 void WindowTreeHostMojo::SetCursorNative(gfx::NativeCursor cursor) {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostMojo::MoveCursorToNative(const gfx::Point& location) {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostMojo::OnCursorVisibilityChangedNative(bool show) {
   NOTIMPLEMENTED();
@@ skipping 14 matching lines @@
     const gfx::Rect& old_bounds,
     const gfx::Rect& new_bounds) {
   bounds_ = new_bounds;
   if (old_bounds.origin() != new_bounds.origin())
     OnHostMoved(bounds_.origin());
   if (old_bounds.size() != new_bounds.size())
     OnHostResized(bounds_.size());
 }
 
 }  // namespace mojo