Make chrome/browser/chrome_browser_main_linux.* Linux-only.

chrome/browser/chrome_browser_main_mac.h

Index: chrome/browser/chrome_browser_main_mac.h
===================================================================
--- chrome/browser/chrome_browser_main_mac.h	(revision 128430)
+++ chrome/browser/chrome_browser_main_mac.h	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -17,12 +17,12 @@
   virtual void PreEarlyInitialization() OVERRIDE;
   virtual void PreMainMessageLoopStart() OVERRIDE;
 
-  // ChromeBrowserMainParts overrides.
-  virtual void ShowMissingLocaleMessageBox() OVERRIDE;
-
   // Perform platform-specific work that needs to be done after the main event
   // loop has ended. The embedder must be sure to call this.
   static void DidEndMainMessageLoop();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainPartsMac);
 };
 
 #endif  // CHROME_BROWSER_CHROME_BROWSER_MAIN_MAC_H_