Move CrTrackingArea from chrome/browser/ui/cocoa to ui/base/cocoa.

ui/base/cocoa/tracking_area.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_TRACKING_AREA_H_
-#define CHROME_BROWSER_UI_COCOA_TRACKING_AREA_H_
+#ifndef UI_BASE_COCOA_TRACKING_AREA_H_
+#define UI_BASE_COCOA_TRACKING_AREA_H_
 
 #import <AppKit/AppKit.h>
 
 #include "base/memory/scoped_nsobject.h"
+#include "ui/base/ui_export.h"
 
 @class CrTrackingAreaOwnerProxy;
 
 // The CrTrackingArea can be used in place of an NSTrackingArea to shut off
 // messaging to the |owner| at a specific point in time.
 @interface CrTrackingArea : NSTrackingArea {
  @private
   scoped_nsobject<CrTrackingAreaOwnerProxy> ownerProxy_;
 }
 
 // Designated initializer. Forwards all arguments to the superclass, but wraps
 // |owner| in a proxy object.
 - (id)initWithRect:(NSRect)rect
            options:(NSTrackingAreaOptions)options
              owner:(id)owner
           userInfo:(NSDictionary*)userInfo;
 
 // Prevents any future messages from being delivered to the |owner|.
 - (void)clearOwner;
 
 // Watches |window| for its NSWindowWillCloseNotification and calls
 // |-clearOwner| when the notification is observed.
 - (void)clearOwnerWhenWindowWillClose:(NSWindow*)window;
 
 @end
 
 // Scoper //////////////////////////////////////////////////////////////////////
 
+namespace ui {
+
 // Use an instance of this class to call |-clearOwner| on the |tracking_area_|
 // when this goes out of scope.
-class ScopedCrTrackingArea {
+class UI_EXPORT ScopedCrTrackingArea {
  public:
   // Takes ownership of |tracking_area| without retaining it.
   explicit ScopedCrTrackingArea(CrTrackingArea* tracking_area = nil);
   ~ScopedCrTrackingArea();
 
   // This will call |scoped_nsobject<>::reset()| to take ownership of the new
   // tracking area.  Note that -clearOwner is NOT called on the existing
   // tracking area.
   void reset(CrTrackingArea* tracking_area = nil);
 
   CrTrackingArea* get() const;
 
  private:
   scoped_nsobject<CrTrackingArea> tracking_area_;
   DISALLOW_COPY_AND_ASSIGN(ScopedCrTrackingArea);
 };
 
-#endif  // CHROME_BROWSER_UI_COCOA_TRACKING_AREA_H_
+}  // namespace ui
+
+#endif  // UI_BASE_COCOA_TRACKING_AREA_H_