Fix event dispatching and window resizing in high-dpi mode.

ui/views/mus/window_tree_host_mus.cc

 // Copyright 2015 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 "ui/views/mus/window_tree_host_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "services/ui/public/cpp/window.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
@@ skipping 29 matching lines @@
 
   SetPlatformWindow(base::MakeUnique<ui::StubWindow>(
       this,
       false));  // Do not advertise accelerated widget; already set manually.
 
   compositor()->SetWindow(window);
 
   // Initialize the stub platform window bounds to those of the ui::Window.
   platform_window()->SetBounds(window->bounds());
 
-  // The location of events is already transformed, and there is no way to
-  // correctly determine the reverse transform. So, don't attempt to transform
-  // event locations, else the root location is wrong.
-  // TODO(sky): we need to transform for device scale though.
-  dispatcher()->set_transform_events(false);
   compositor()->SetHostHasTransparentBackground(true);
 
   input_method_ = base::MakeUnique<InputMethodMus>(this, window);
   SetSharedInputMethod(input_method_.get());
 }
 
 WindowTreeHostMus::~WindowTreeHostMus() {
   DestroyCompositor();
   DestroyDispatcher();
 }
@@ skipping 28 matching lines @@
 void WindowTreeHostMus::OnCloseRequest() {
   OnHostCloseRequested();
 }
 
 gfx::ICCProfile WindowTreeHostMus::GetICCProfileForCurrentDisplay() {
   // TODO: This should read the profile from mus. crbug.com/647510
   return gfx::ICCProfile();
 }
 
 }  // namespace views