aura: Remove WindowTreeHost::OnDeviceScaleFactorChanged.

mojo/services/view_manager/window_tree_host_impl.cc

 // Copyright 2013 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/services/view_manager/root_node_manager.h"
 #include "mojo/services/view_manager/window_tree_host_impl.h"
 #include "mojo/public/c/gles2/gles2.h"
 #include "mojo/services/public/cpp/geometry/geometry_type_converters.h"
 #include "mojo/services/view_manager/context_factory_impl.h"
 #include "ui/aura/env.h"
@@ skipping 124 matching lines @@
 
 void WindowTreeHostImpl::ReleaseCapture() {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostImpl::PostNativeEvent(
     const base::NativeEvent& native_event) {
   NOTIMPLEMENTED();
 }
 
-void WindowTreeHostImpl::OnDeviceScaleFactorChanged(float device_scale_factor) {
-  NOTIMPLEMENTED();
-}
-
 void WindowTreeHostImpl::SetCursorNative(gfx::NativeCursor cursor) {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostImpl::MoveCursorToNative(const gfx::Point& location) {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostImpl::OnCursorVisibilityChangedNative(bool show) {
   NOTIMPLEMENTED();
@@ skipping 56 matching lines @@
       break;
     }
     // TODO(beng): touch, etc.
   }
   callback.Run();
 };
 
 }  // namespace service
 }  // namespace view_manager
 }  // namespace mojo