Enable Clang warnings in .cc files for Linux+[Aura/ChromeOS]

ash/system/chromeos/network/tray_network.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 "ash/system/chromeos/network/tray_network.h"
 
 #include "ash/ash_switches.h"
 #include "ash/shell.h"
 #include "ash/system/chromeos/network/network_icon_animation.h"
 #include "ash/system/chromeos/network/network_list_detailed_view.h"
@@ skipping 113 matching lines @@
           GetMostRelevantNetworkIcon(&info, false);
       UpdateIcon(info.tray_icon_visible, info.image);
     }
   }
 
   virtual ~NetworkTrayView() {
     if (UseNewNetworkHandlers())
       network_icon::NetworkIconAnimation::GetInstance()->RemoveObserver(this);
   }
 
-  std::string GetClassName() const { return "NetworkTrayView"; }
+  virtual std::string GetClassName() const OVERRIDE {
+    return "NetworkTrayView";
+  }
 
   void Update(const NetworkIconInfo& info) {
     if (UseNewNetworkHandlers())
       return;
     UpdateIcon(info.tray_icon_visible, info.image);
     UpdateConnectionStatus(info.name, info.connected);
   }
 
   void UpdateNetworkStateHandlerIcon() {
     DCHECK(UseNewNetworkHandlers());
@@ skipping 491 matching lines @@
 
 void TrayNetwork::LinkClicked(MessageType message_type, int link_id) {
   tray::NetworkMessages::MessageMap::const_iterator iter =
       messages()->messages().find(message_type);
   if (iter != messages()->messages().end() && iter->second.delegate)
     iter->second.delegate->NotificationLinkClicked(message_type, link_id);
 }
 
 }  // namespace internal
 }  // namespace ash