Enhanced the InkDropRippleImpl to create/destroy InkDropAnimations as needed.

ui/views/animation/ink_drop_state.h

 // 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.
 
 #ifndef UI_VIEWS_ANIMATION_INK_DROP_STATE_H_
 #define UI_VIEWS_ANIMATION_INK_DROP_STATE_H_
 
+#include <iosfwd>
+#include <string>
+
+#include "ui/views/views_export.h"
+
 namespace views {
 
 // The different states that the ink drop animation can be animated to.
 enum class InkDropState {
   // The ink drop is not visible.
   HIDDEN,
   // The view is being interacted with but the action to be triggered has not
   // yet been determined.
   ACTION_PENDING,
-  // The quick action for the view has been triggered. e.g. A tap gesture to
+  // The quick action for the view has been triggered. e.g. a tap gesture to
   // click a button.
   QUICK_ACTION,
   // A view is being interacted with and the pending action will be a 'slow'
-  // action. e.g. A long press that is still active before releasing.
+  // action. e.g. a long press that is still active before releasing.
   SLOW_ACTION_PENDING,
-  // The slow action for the view has been triggered. e.g. A long press release
+  // The slow action for the view has been triggered. e.g. a long press release
   // to bring up a menu.
   SLOW_ACTION,
   // An active state for a view that is not currently being interacted with.
-  // e.g. A pressed button that is showing a menu.
+  // e.g. a pressed button that is showing a menu.
   ACTIVATED,
-  // A previously active state has been toggled to inactive. e.g. A drop down
+  // A previously active state has been toggled to inactive. e.g. a drop down
   // menu is closed.
   DEACTIVATED,
 };
 
+// Returns a human readable string for |state|.  Useful for logging.
+std::string ToString(InkDropState state);
+
 }  // namespace views
 
 #endif  // UI_VIEWS_ANIMATION_INK_DROP_STATE_H_