Converts chrome to aura-mus

ui/views/mus/desktop_window_tree_host_mus.cc

 // Copyright 2016 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/desktop_window_tree_host_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/cursor_client.h"
 #include "ui/aura/client/drag_drop_client.h"
@@ skipping 162 matching lines @@
     DesktopNativeWidgetAura* desktop_native_widget_aura,
     const std::map<std::string, std::vector<uint8_t>>* mus_properties)
     : aura::WindowTreeHostMus(MusClient::Get()->window_tree_client(),
                               mus_properties),
       native_widget_delegate_(native_widget_delegate),
       desktop_native_widget_aura_(desktop_native_widget_aura),
       fullscreen_restore_state_(ui::SHOW_STATE_DEFAULT),
       close_widget_factory_(this) {
   aura::Env::GetInstance()->AddObserver(this);
   MusClient::Get()->AddObserver(this);
+  // DesktopNativeWidgetAura registers the association between |content_window_|
+  // and Widget, but code may also want to go from the root (window()) to the
+  // Widget. This call enables that.
+  NativeWidgetAura::RegisterNativeWidgetForWindow(desktop_native_widget_aura,
+                                                  window());
   // TODO: use display id and bounds if available, likely need to pass in
   // InitParams for that.
 }
 
 DesktopWindowTreeHostMus::~DesktopWindowTreeHostMus() {
   MusClient::Get()->RemoveObserver(this);
   aura::Env::GetInstance()->RemoveObserver(this);
   desktop_native_widget_aura_->OnDesktopWindowTreeHostDestroyed(this);
 }
 
@@ skipping 510 matching lines @@
   if (window == this->window()) {
     is_active_ = true;
     desktop_native_widget_aura_->HandleActivationChanged(true);
   } else if (is_active_) {
     is_active_ = false;
     desktop_native_widget_aura_->HandleActivationChanged(false);
   }
 }
 
 }  // namespace views