Add missing include guards in Cocoa code.

chrome/browser/ui/cocoa/dock_icon.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 CHROME_BROWSER_UI_COCOA_DOCK_ICON_H_
+#define CHROME_BROWSER_UI_COCOA_DOCK_ICON_H_
+
 #import <Cocoa/Cocoa.h>
 
 #include "base/time/time.h"
 
 // A class representing the dock icon of the Chromium app. It's its own class
 // since several parts of the app want to manipulate the display of the dock
 // icon.
 //
 // Like all UI, it must only be messaged from the UI thread.
 @interface DockIcon : NSObject {
@@ skipping 17 matching lines @@
 - (void)setDownloads:(int)downloads;
 
 // Indicates whether the progress indicator should be in an indeterminate state
 // or not.
 - (void)setIndeterminate:(BOOL)indeterminate;
 
 // Indicates the amount of progress made of the download. Ranges from [0..1].
 - (void)setProgress:(float)progress;
 
 @end
+
+#endif  // CHROME_BROWSER_UI_COCOA_DOCK_ICON_H_