Fixed all unused-variable Clang warnings on Windows.

content/common/plugin_list_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 "content/common/plugin_list.h"
 
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/file_version_info.h"
@@ skipping 10 matching lines @@
 #include "base/win/registry.h"
 #include "base/win/scoped_handle.h"
 #include "base/win/windows_version.h"
 #include "content/common/plugin_constants_win.h"
 
 namespace content {
 namespace {
 
 const base::char16 kRegistryApps[] =
     L"Software\\Microsoft\\Windows\\CurrentVersion\\App Paths";
-const base::char16 kRegistryFirefox[] = L"firefox.exe";
 const base::char16 kRegistryAcrobat[] = L"Acrobat.exe";
 const base::char16 kRegistryAcrobatReader[] = L"AcroRd32.exe";
 const base::char16 kRegistryWindowsMedia[] = L"wmplayer.exe";
 const base::char16 kRegistryQuickTime[] = L"QuickTimePlayer.exe";
 const base::char16 kRegistryPath[] = L"Path";
 const base::char16 kRegistryFirefoxInstalled[] =
     L"SOFTWARE\\Mozilla\\Mozilla Firefox";
 const base::char16 kRegistryJava[] =
     L"Software\\JavaSoft\\Java Runtime Environment";
 const base::char16 kRegistryBrowserJavaVersion[] = L"BrowserJavaVersion";
@@ skipping 437 matching lines @@
     return false;
 #else
   // The plugin in question could be a 64 bit plugin which we cannot load.
   if (!IsValid32BitImage(base::MakeAbsoluteFilePath(plugin_path)))
     return false;
 #endif
   return true;
 }
 
 }  // namespace content