fix for 27454 - Fade out close button state on mouse exit

chrome/browser/ui/cocoa/hover_button.mm

 // Copyright (c) 2010 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.
 
 #import "chrome/browser/ui/cocoa/hover_button.h"
+#import "chrome/browser/ui/cocoa/tracking_area.h"
 
 @implementation HoverButton
 
+@synthesize hoverState = hoverState_;
+
 - (id)initWithFrame:(NSRect)frameRect {
   if ((self = [super initWithFrame:frameRect])) {
     [self setTrackingEnabled:YES];
     hoverState_ = kHoverStateNone;
     [self updateTrackingAreas];
   }
   return self;
 }
 
 - (void)awakeFromNib {
   [self setTrackingEnabled:YES];
-  hoverState_ = kHoverStateNone;
+  self.hoverState = kHoverStateNone;
   [self updateTrackingAreas];
 }
 
 - (void)dealloc {
   [self setTrackingEnabled:NO];
   [super dealloc];
 }
 
 - (void)mouseEntered:(NSEvent*)theEvent {
-  hoverState_ = kHoverStateMouseOver;
-  [self setNeedsDisplay:YES];
+  self.hoverState = kHoverStateMouseOver;
 }
 
 - (void)mouseExited:(NSEvent*)theEvent {
-  hoverState_ = kHoverStateNone;
-  [self setNeedsDisplay:YES];
+  self.hoverState = kHoverStateNone;
 }
 
 - (void)mouseDown:(NSEvent*)theEvent {
-  hoverState_ = kHoverStateMouseDown;
-  [self setNeedsDisplay:YES];
+  self.hoverState = kHoverStateMouseDown;
   // The hover button needs to hold onto itself here for a bit.  Otherwise,
   // it can be freed while |super mouseDown:| is in it's loop, and the
   // |checkImageState| call will crash.
   // http://crbug.com/28220
   scoped_nsobject<HoverButton> myself([self retain]);
 
   [super mouseDown:theEvent];
   // We need to check the image state after the mouseDown event loop finishes.
   // It's possible that we won't get a mouseExited event if the button was
   // moved under the mouse during tab resize, instead of the mouse moving over
   // the button.
   // http://crbug.com/31279
   [self checkImageState];
 }
 
 - (void)setTrackingEnabled:(BOOL)enabled {
   if (enabled) {
     trackingArea_.reset(
-        [[NSTrackingArea alloc] initWithRect:[self bounds]
+        [[CrTrackingArea alloc] initWithRect:[self bounds]
                                      options:NSTrackingMouseEnteredAndExited |
                                              NSTrackingActiveAlways
-                                       owner:self
+                                proxiedOwner:self
                                     userInfo:nil]);
     [self addTrackingArea:trackingArea_.get()];
 
     // If you have a separate window that overlaps the close button, and you
     // move the mouse directly over the close button without entering another
     // part of the tab strip, we don't get any mouseEntered event since the
     // tracking area was disabled when we entered.
-    [self checkImageState];
+    // Done with a delay of 0 because sometimes an event appears to be missed
+    // between the activation of the tracking area and the call to
+    // checkImageState resulting in the button state being incorrect.
+    [self performSelector:@selector(checkImageState)
+               withObject:nil
+               afterDelay:0];
   } else {
     if (trackingArea_.get()) {
       [self removeTrackingArea:trackingArea_.get()];
       trackingArea_.reset(nil);
     }
   }
 }
 
 - (void)updateTrackingAreas {
   [super updateTrackingAreas];
   [self checkImageState];
 }
 
 - (void)checkImageState {
   if (!trackingArea_.get())
     return;
 
   // Update the button's state if the button has moved.
   NSPoint mouseLoc = [[self window] mouseLocationOutsideOfEventStream];
   mouseLoc = [self convertPoint:mouseLoc fromView:nil];
-  hoverState_ = NSPointInRect(mouseLoc, [self bounds]) ?
+  self.hoverState = NSPointInRect(mouseLoc, [self bounds]) ?
       kHoverStateMouseOver : kHoverStateNone;
+}
+
+- (void)setHoverState:(HoverState)state {
+  hoverState_ = state;
   [self setNeedsDisplay:YES];
 }
 
 @end