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

ui/views/animation/ink_drop_animation_controller_factory_unittest.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 "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/test/test_mock_time_task_runner.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/timer/timer.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 79 matching lines @@
 // Note: First argument is optional and intentionally left blank.
 // (it's a prefix for the generated test cases)
 INSTANTIATE_TEST_CASE_P(
     ,
     InkDropAnimationControllerFactoryTest,
     testing::Values(ui::MaterialDesignController::NON_MATERIAL,
                     ui::MaterialDesignController::MATERIAL_NORMAL,
                     ui::MaterialDesignController::MATERIAL_HYBRID));
 
 TEST_P(InkDropAnimationControllerFactoryTest,
-       VerifyAllInkDropLayersRemovedAfterDestruction) {
+       VerifyInkDropLayersRemovedAfterDestructionWhenRippleIsActive) {
   ink_drop_animation_controller_->AnimateToState(InkDropState::ACTION_PENDING);
   ink_drop_animation_controller_.reset();
   EXPECT_EQ(0, test_ink_drop_host_.num_ink_drop_layers());
 }
 
+TEST_P(InkDropAnimationControllerFactoryTest,
+       VerifyInkDropLayersRemovedAfterDestructionWhenHoverIsActive) {
+  test_ink_drop_host_.set_should_show_hover(true);
+  ink_drop_animation_controller_->SetHovered(true);
+  ink_drop_animation_controller_.reset();
+  EXPECT_EQ(0, test_ink_drop_host_.num_ink_drop_layers());
+}
+
 TEST_P(InkDropAnimationControllerFactoryTest, StateIsHiddenInitially) {
   EXPECT_EQ(InkDropState::HIDDEN,
             ink_drop_animation_controller_->GetTargetInkDropState());
 }
 
 TEST_P(InkDropAnimationControllerFactoryTest, TypicalQuickAction) {
   ink_drop_animation_controller_->AnimateToState(InkDropState::ACTION_PENDING);
   ink_drop_animation_controller_->AnimateToState(
       InkDropState::ACTION_TRIGGERED);
   EXPECT_EQ(InkDropState::HIDDEN,
@@ skipping 38 matching lines @@
   ink_drop_animation_controller_->AnimateToState(InkDropState::ACTION_PENDING);
   ink_drop_animation_controller_->AnimateToState(
       InkDropState::ALTERNATE_ACTION_PENDING);
   ink_drop_animation_controller_->AnimateToState(InkDropState::ACTIVATED);
   ink_drop_animation_controller_->AnimateToState(InkDropState::DEACTIVATED);
   EXPECT_EQ(InkDropState::HIDDEN,
             ink_drop_animation_controller_->GetTargetInkDropState());
 }
 
 }  // namespace views