[Mac] Reimplement HoverButton and HoverImageButton using NSButton.state.

ui/base/cocoa/hover_button.h

 // Copyright (c) 2011 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_BASE_COCOA_HOVER_BUTTON_
 #define UI_BASE_COCOA_HOVER_BUTTON_
 
 #import <Cocoa/Cocoa.h>
 
 #import "base/memory/scoped_nsobject.h"
 #import "ui/base/cocoa/tracking_area.h"
 #import "ui/base/ui_export.h"
 
 // A button that changes when you hover over it and click it.
 UI_EXPORT
 @interface HoverButton : NSButton {
  @protected
   // Enumeration of the hover states that the close button can be in at any one
   // time. The button cannot be in more than one hover state at a time.
   enum HoverState {
     kHoverStateNone = 0,
     kHoverStateMouseOver = 1,
     kHoverStateMouseDown = 2
   };
 
-  HoverState hoverState_;
+  // Whether the user is mousing inside the button.
+  BOOL isMouseInside_;
 
  @private
   // Tracking area for button mouseover states. Nil if not enabled.
   ui::ScopedCrTrackingArea trackingArea_;
 }
 
-@property(nonatomic) HoverState hoverState;
+@property(nonatomic) BOOL isMouseInside;

[sail, 2013/06/05 20:06:22]

nonatomic, assign?

[Robert Sesek, 2013/06/05 20:23:21]

Done.

+@property(nonatomic, readonly) HoverState hoverState;
 
-// Enables or disables the tracking for the button.
+// Enables or disables the hover tracking for the button.
 - (void)setTrackingEnabled:(BOOL)enabled;
 
 // Checks to see whether the mouse is in the button's bounds and update
 // the image in case it gets out of sync.  This occurs to the close button
 // when you close a tab so the tab to the left of it takes its place, and
 // drag the button without moving the mouse before you press the button down.
 - (void)checkImageState;
 
 @end
 
 #endif  // UI_BASE_COCOA_HOVER_BUTTON_