Replace instances of LINUX2 with OS_CHROMEOS and linux2 with chromeos.

chrome/browser/browser.h

 // Copyright (c) 2006-2009 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_BROWSER_H_
 #define CHROME_BROWSER_BROWSER_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 351 matching lines @@
   void OpenBookmarkManager();
   void ShowHistoryTab();
   void ShowDownloadsTab();
   void OpenClearBrowsingDataDialog();
   void OpenOptionsDialog();
   void OpenKeywordEditor();
   void OpenPasswordManager();
   void OpenImportSettingsDialog();
   void OpenAboutChromeDialog();
   void OpenHelpTab();
-#if defined(LINUX2)
+#if defined(OS_CHROMEOS)
   void ShowControlPanel();
 #endif
 
   virtual void UpdateDownloadShelfVisibility(bool visible);
 
   /////////////////////////////////////////////////////////////////////////////
 
   static void RegisterPrefs(PrefService* prefs);
   static void RegisterUserPrefs(PrefService* prefs);
 
@@ skipping 370 matching lines @@
   // The browser idle task helps cleanup unused memory resources when idle.
   scoped_ptr<BrowserIdleTimer> idle_task_;
 
   // Keep track of the encoding auto detect pref.
   BooleanPrefMember encoding_auto_detect_;
 
   DISALLOW_COPY_AND_ASSIGN(Browser);
 };
 
 #endif  // CHROME_BROWSER_BROWSER_H_