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

chrome/browser/ui/cocoa/animation_utils.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 CHROME_BROWSER_UI_COCOA_ANIMATION_UTILS_H
 #define CHROME_BROWSER_UI_COCOA_ANIMATION_UTILS_H
 #pragma once
 
 #import <Cocoa/Cocoa.h>
 
@@ skipping 13 matching lines @@
   WithNoAnimation() {
     [NSAnimationContext beginGrouping];
     [[NSAnimationContext currentContext] setDuration:0.0];
   }
 
   ~WithNoAnimation() {
    [NSAnimationContext endGrouping];
   }
 };
 
+// Disables actions within a scope.
+class ScopedCAActionDisabler {
+ public:
+  ScopedCAActionDisabler() {
+    [CATransaction begin];
+    [CATransaction setValue:[NSNumber numberWithBool:YES]
+                     forKey:kCATransactionDisableActions];
+  }
+
+  ~ScopedCAActionDisabler() {
+    [CATransaction commit];
+  }
+};
+
+// Sets a duration on actions within a scope.
+class ScopedCAActionSetDuration {
+ public:
+  explicit ScopedCAActionSetDuration(NSTimeInterval duration) {
+    [CATransaction begin];
+    [CATransaction setValue:[NSNumber numberWithFloat:duration]
+                     forKey:kCATransactionAnimationDuration];
+  }
+
+  ~ScopedCAActionSetDuration() {
+    [CATransaction commit];
+  }
+};
 
 #endif // CHROME_BROWSER_UI_COCOA_ANIMATION_UTILS_H