Fix some extern usage in .cc files.

chrome/common/chrome_switches.cc

 // 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.
 
 #include "chrome/common/chrome_switches.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 
 namespace switches {
@@ skipping 535 matching lines @@
 // Enables fanciful thumbnail processing. Used with NTP for
 // instant-extended-api, where thumbnails are generally smaller.
 const char kEnableThumbnailRetargeting[]   = "enable-thumbnail-retargeting";
 
 // Enables Alternate-Protocol when the port is user controlled (> 1024).
 const char kEnableUserAlternateProtocolPorts[] =
     "enable-user-controlled-alternate-protocol-ports";
 
 // Enables a new "web app" style frame for hosted apps (including bookmark
 // apps).
-extern const char kEnableWebAppFrame[] = "enable-web-app-frame";
+const char kEnableWebAppFrame[] = "enable-web-app-frame";
 
 // Enables synchronizing WiFi credentials across devices, using Chrome Sync.
 const char kEnableWifiCredentialSync[]      = "enable-wifi-credential-sync";
 
 // Values for the kExtensionContentVerification flag.
 // See ContentVerifierDelegate::Mode for more explanation.
 const char kExtensionContentVerificationBootstrap[] = "bootstrap";
 const char kExtensionContentVerificationEnforceStrict[] = "enforce_strict";
 const char kExtensionContentVerificationEnforce[] = "enforce";
 
@@ skipping 830 matching lines @@
 
 // -----------------------------------------------------------------------------
 // DO NOT ADD YOUR CRAP TO THE BOTTOM OF THIS FILE.
 //
 // You were going to just dump your switches here, weren't you? Instead, please
 // put them in alphabetical order above, or in order inside the appropriate
 // ifdef at the bottom. The order should match the header.
 // -----------------------------------------------------------------------------
 
 }  // namespace switches