Add MD Ink Drop Layers to InkDropHost only when a ripple/hover is active.

ui/views/animation/test/ink_drop_animation_test_api.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/animation/test/ink_drop_animation_test_api.h"
 
-#include "base/time/time.h"
-#include "ui/compositor/layer.h"
-#include "ui/compositor/layer_animator.h"
-#include "ui/compositor/test/layer_animator_test_controller.h"
-#include "ui/views/animation/ink_drop_animation.h"
-
 namespace views {
 namespace test {
 
 InkDropAnimationTestApi::InkDropAnimationTestApi(
     InkDropAnimation* ink_drop_animation)
     : ui::test::MultiLayerAnimatorTestController(this),
       ink_drop_animation_(ink_drop_animation) {}
 
 InkDropAnimationTestApi::~InkDropAnimationTestApi() {}
 
 std::vector<ui::LayerAnimator*> InkDropAnimationTestApi::GetLayerAnimators() {
   return std::vector<ui::LayerAnimator*>();
 }
 
 }  // namespace test
 }  // namespace views