MacViews: Handle Space and Return keys correctly for Buttons.

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 11 matching lines @@
 // part of the focus chain, unless in accessibility mode. Call
 // SetFocusForPlatform() to make it part of the focus chain.
 class VIEWS_EXPORT CustomButton : public Button, public gfx::AnimationDelegate {
  public:
   // An enum describing the events on which a button should notify its listener.
   enum NotifyAction {
     NOTIFY_ON_PRESS,
     NOTIFY_ON_RELEASE,
   };
 
+  // An enum describing the events on which a button should be clicked for a
+  // given key event.
+  enum ClickAction {
+    CLICK_ON_PRESS,

[tapted, 2017/01/05 00:34:41]

I toyed with buttons a bit manually, and realised this could be confused with a
mouse press, which never causes a "click". So perhaps

CLICK_ON_KEY_PRESS / CLICK_ON_KEY_RELEASE

and ClickAction -> KeyClickAction?

[karandeepb, 2017/01/05 10:50:08]

Done.

+    CLICK_ON_RELEASE,
+    CLICK_NONE,
+  };
+
   // The menu button's class name.
   static const char kViewClassName[];
 
   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_; }
@@ skipping 151 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_