ash: Do not use MessageLoopForUI when not needed.

ash/display/display_animator_chromeos.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 "ash/display/display_animator_chromeos.h"
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "base/bind.h"
 #include "base/stl_util.h"
+#include "base/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/compositor/layer_animation_sequence.h"
 #include "ui/compositor/layer_animator.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 
 namespace ash {
@@ skipping 12 matching lines @@
   void AddNewAnimator(ui::LayerAnimator* animator) {
     Observer* observer = new Observer(animator, this);
     animator->AddObserver(observer);
     observer_list_.push_back(observer);
   }
 
  private:
   void OnSingleTaskCompleted() {
     completed_counter_++;
     if (completed_counter_ >= observer_list_.size()) {
-      base::MessageLoopForUI::current()->DeleteSoon(FROM_HERE, this);
+      base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, this);
       if (!animation_aborted_)
-        base::MessageLoopForUI::current()->PostTask(FROM_HERE, callback_);
+        base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, callback_);
     }
   }
 
   void OnSingleTaskAborted() {
     animation_aborted_ = true;
     OnSingleTaskCompleted();
   }
 
   // The actual observer to listen each animation completion.
   class Observer : public ui::LayerAnimationObserver {
@@ skipping 148 matching lines @@
   if (timer_) {
     timer_->Stop();
     timer_.reset();
   }
   STLDeleteContainerPairSecondPointers(hiding_layers_.begin(),
                                        hiding_layers_.end());
   hiding_layers_.clear();
 }
 
 }  // namespace ash