CustomButton: restrict animation repaints to buttons that actually animate

ui/views/controls/button/custom_button.h

 // Copyright (c) 2012 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_CONTROLS_BUTTON_CUSTOM_BUTTON_H_
 #define UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 24 matching lines @@
   static const CustomButton* AsCustomButton(const View* view);
   static CustomButton* AsCustomButton(View* view);
 
   ~CustomButton() override;
 
   // Get/sets the current display state of the button.
   ButtonState state() const { return state_; }
   void SetState(ButtonState state);
 
   // Starts throbbing. See HoverAnimation for a description of cycles_til_stop.
+  // This method does nothing if |animate_on_state_change_| is false.
   void StartThrobbing(int cycles_til_stop);
 
   // Stops throbbing immediately.
   void StopThrobbing();
 
   // Set how long the hover animation will last for.
   void SetAnimationDuration(int duration);
 
   void set_triggerable_event_flags(int triggerable_event_flags) {
     triggerable_event_flags_ = triggerable_event_flags;
@@ skipping 103 matching lines @@
 
   const gfx::ThrobAnimation& hover_animation() const {
     return hover_animation_;
   }
 
  private:
   ButtonState state_;
 
   gfx::ThrobAnimation hover_animation_;
 
-  // Should we animate when the state changes? Defaults to true.
-  bool animate_on_state_change_;
+  // Should we animate when the state changes?
+  bool animate_on_state_change_ = false;
 
   // Is the hover animation running because StartThrob was invoked?
   bool is_throbbing_;
 
   // Mouse event flags which can trigger button actions.
   int triggerable_event_flags_;
 
   // See description above setter.
   bool request_focus_on_press_;
 
@@ skipping 10 matching lines @@
 
   // The color of the ripple and hover.
   SkColor ink_drop_base_color_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_