Fixes and test updates for aura-mus

ui/aura/mus/window_port_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/aura/mus/window_port_mus.h"
 
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/transient_window_client.h"
 #include "ui/aura/mus/property_converter.h"
 #include "ui/aura/mus/surface_id_handler.h"
 #include "ui/aura/mus/window_tree_client.h"
 #include "ui/aura/mus/window_tree_client_delegate.h"
 #include "ui/aura/window.h"
+#include "ui/aura/window_delegate.h"
 #include "ui/aura/window_observer.h"
 #include "ui/aura/window_property.h"
 
 namespace aura {
 
 WindowPortMus::WindowMusChangeDataImpl::WindowMusChangeDataImpl() = default;
 
 WindowPortMus::WindowMusChangeDataImpl::~WindowMusChangeDataImpl() = default;
 
 // static
@@ skipping 275 matching lines @@
 void WindowPortMus::NotifyEmbeddedAppDisconnected() {
   for (WindowObserver& observer : *GetObservers(window_))
     observer.OnEmbeddedAppDisconnected(window_);
 }
 
 void WindowPortMus::OnPreInit(Window* window) {
   window_ = window;
   window_tree_client_->OnWindowMusCreated(this);
 }
 
-void WindowPortMus::OnDeviceScaleFactorChanged(float device_scale_factor) {}
+void WindowPortMus::OnDeviceScaleFactorChanged(float device_scale_factor) {
+  if (window_->delegate())
+    window_->delegate()->OnDeviceScaleFactorChanged(device_scale_factor);
+}
 
 void WindowPortMus::OnWillAddChild(Window* child) {
   ServerChangeData change_data;
   change_data.child_id = Get(child)->server_id();
   if (!RemoveChangeByTypeAndData(ServerChangeType::ADD, change_data))
     window_tree_client_->OnWindowMusAddChild(this, Get(child));
 }
 
 void WindowPortMus::OnWillRemoveChild(Window* child) {
   ServerChangeData change_data;
@@ skipping 36 matching lines @@
   change_data.property_name =
       GetPropertyConverter()->GetTransportNameForPropertyKey(key);
   // TODO(sky): investigate to see if we need to compare data. In particular do
   // we ever have a case where changing a property cascades into changing the
   // same property?
   if (!RemoveChangeByTypeAndData(ServerChangeType::PROPERTY, change_data))
     window_tree_client_->OnWindowMusPropertyChanged(this, key, std::move(data));
 }
 
 }  // namespace aura