Add missing include guards in Cocoa code.

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_bridge.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.
 
-// C++ bridge class between Chromium and Cocoa to connect the
-// Bookmarks (model) with the Bookmark Bar (view).
-//
-// There is exactly one BookmarkBarBridge per BookmarkBarController /
-// BrowserWindowController / Browser.
-
 #ifndef CHROME_BROWSER_UI_COCOA_BOOKMARKS_BOOKMARK_BAR_BRIDGE_H_
 #define CHROME_BROWSER_UI_COCOA_BOOKMARKS_BOOKMARK_BAR_BRIDGE_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "components/bookmarks/browser/bookmark_model_observer.h"
 #include "components/prefs/pref_change_registrar.h"
 
 class Profile;
 @class BookmarkBarController;
 
+// C++ bridge class between Chromium and Cocoa to connect the
+// Bookmarks (model) with the Bookmark Bar (view).
+//
+// There is exactly one BookmarkBarBridge per BookmarkBarController /
+// BrowserWindowController / Browser.
 class BookmarkBarBridge : public bookmarks::BookmarkModelObserver {
  public:
   BookmarkBarBridge(Profile* profile,
                     BookmarkBarController* controller,
                     bookmarks::BookmarkModel* model);
   ~BookmarkBarBridge() override;
 
   // bookmarks::BookmarkModelObserver:
   void BookmarkModelLoaded(bookmarks::BookmarkModel* model,
                            bool ids_reassigned) override;
@@ skipping 33 matching lines @@
   PrefChangeRegistrar profile_pref_registrar_;
 
   // Updates the visibility of the apps shortcut and the managed bookmarks
   // folder based on the pref values.
   void OnExtraButtonsVisibilityChanged();
 
   DISALLOW_COPY_AND_ASSIGN(BookmarkBarBridge);
 };
 
 #endif  // CHROME_BROWSER_UI_COCOA_BOOKMARKS_BOOKMARK_BAR_BRIDGE_H_