Enable MSVC warning for unused locals.

chrome/browser/process_singleton_win.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/browser/process_singleton.h"
 
 #include <shellapi.h>
 
 #include "base/base_paths.h"
 #include "base/bind.h"
@@ skipping 142 matching lines @@
 bool ProcessLaunchNotification(
     const ProcessSingleton::NotificationCallback& notification_callback,
     UINT message,
     WPARAM wparam,
     LPARAM lparam,
     LRESULT* result) {
   if (message != WM_COPYDATA)
     return false;
 
   // Handle the WM_COPYDATA message from another process.
-  HWND hwnd = reinterpret_cast<HWND>(wparam);
   const COPYDATASTRUCT* cds = reinterpret_cast<COPYDATASTRUCT*>(lparam);
 
   CommandLine parsed_command_line(CommandLine::NO_PROGRAM);
   base::FilePath current_directory;
   if (!ParseCommandLine(cds, &parsed_command_line, &current_directory)) {
     *result = TRUE;
     return true;
   }
 
   *result = notification_callback.Run(parsed_command_line, current_directory) ?
@@ skipping 281 matching lines @@
           ::SetEvent(metro_activation_event.Get());
       }
     }
   }
 
   return window_.hwnd() != NULL;
 }
 
 void ProcessSingleton::Cleanup() {
 }