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

ui/views/animation/ink_drop_animation_controller_factory_unittest.cc

Index: ui/views/animation/ink_drop_animation_controller_factory_unittest.cc
diff --git a/ui/views/animation/ink_drop_animation_controller_factory_unittest.cc b/ui/views/animation/ink_drop_animation_controller_factory_unittest.cc
index 2d430edcaeb98a023e20de69088e2be5f306bfe6..c75b2c23d7bfb47d119303ddaeaf4f65b0cc12d4 100644
--- a/ui/views/animation/ink_drop_animation_controller_factory_unittest.cc
+++ b/ui/views/animation/ink_drop_animation_controller_factory_unittest.cc
@@ -97,12 +97,20 @@ INSTANTIATE_TEST_CASE_P(
                     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());