Pressing spacebar on toolbar buttons triggers the ripple effect.

ui/views/animation/test/test_ink_drop_delegate.h

 // Copyright 2016 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_TEST_TEST_INK_DROP_DELEGATE_H_
 #define UI_VIEWS_ANIMATION_TEST_TEST_INK_DROP_DELEGATE_H_
 
 #include "base/macros.h"
 #include "ui/views/animation/ink_drop_delegate.h"
 
 namespace views {
 namespace test {
 
 class TestInkDropDelegate : public InkDropDelegate {
  public:
   TestInkDropDelegate();
   ~TestInkDropDelegate() override;
 
-  InkDropState state() const { return state_; }
-

[kylix_rd, 2016/05/13 22:58:21]

Since InkDropDelegate can now return the current state, this method is now
redundant.

   bool is_hovered() const { return is_hovered_; }
 
   // InkDropDelegate:
   void OnAction(InkDropState state) override;
   void SnapToActivated() override;
   void SetHovered(bool is_hovered) override;
+  InkDropState GetTargetInkDropState() const override;
 
  private:
   InkDropState state_;
 
   bool is_hovered_;
 
   DISALLOW_COPY_AND_ASSIGN(TestInkDropDelegate);
 };
 
 }  // namespace test
 }  // namespace views
 
 #endif  // UI_VIEWS_ANIMATION_TEST_TEST_INK_DROP_DELEGATE_H_