Use ScopedTaskEnvironment instead of MessageLoopForUI in ui tests.

ui/gfx/animation/animation_container_unittest.cc

 // Copyright (c) 2011 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/gfx/animation/animation_container.h"
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/animation/animation_container_observer.h"
 #include "ui/gfx/animation/linear_animation.h"
 #include "ui/gfx/animation/test_animation_delegate.h"
 
 namespace gfx {
 
 namespace {
 
 class FakeAnimationContainerObserver : public AnimationContainerObserver {
@@ skipping 30 matching lines @@
 
   void AnimateToState(double state) override {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestAnimation);
 };
 
 }  // namespace
 
 class AnimationContainerTest: public testing::Test {
+ protected:
+  AnimationContainerTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI) {}
+
  private:
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 };
 
 // Makes sure the animation ups the ref count of the container and releases it
 // appropriately.
 TEST_F(AnimationContainerTest, Ownership) {
   TestAnimationDelegate delegate;
   scoped_refptr<AnimationContainer> container(new AnimationContainer());
   std::unique_ptr<Animation> animation(new TestAnimation(&delegate));
   animation->SetContainer(container.get());
   // Setting the container should up the ref count.
@@ skipping 57 matching lines @@
 
   EXPECT_TRUE(observer.empty());
 
   // And the container should no longer be running.
   EXPECT_FALSE(container->is_running());
 
   container->set_observer(NULL);
 }
 
 }  // namespace gfx