clang/win: Let some chromium_code targets build with -Wextra.

content/child/npapi/webplugin_delegate_impl_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/child/npapi/webplugin_delegate_impl.h"
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 151 matching lines @@
     return L"";
 
   ZwQueryKeyType func = reinterpret_cast<ZwQueryKeyType>(
       ::GetProcAddress(dll, "ZwQueryKey"));
   if (func == NULL)
     return L"";
 
   DWORD size = 0;
   DWORD result = 0;
   result = func(key, KeyNameInformation, 0, 0, &size);
-  if (result != STATUS_BUFFER_TOO_SMALL)
+  if (result != static_cast<DWORD>(STATUS_BUFFER_TOO_SMALL))
     return L"";
 
   scoped_ptr<char[]> buffer(new char[size]);
   if (buffer.get() == NULL)
     return L"";
 
   result = func(key, KeyNameInformation, buffer.get(), size, &size);
-  if (result != STATUS_SUCCESS)
+  if (result != static_cast<DWORD>(STATUS_SUCCESS))
     return L"";
 
   KEY_NAME_INFORMATION* info =
       reinterpret_cast<KEY_NAME_INFORMATION*>(buffer.get());
   return std::wstring(info->Name, info->NameLength / sizeof(wchar_t));
 }
 
 uint32_t GetPluginMajorVersion(const WebPluginInfo& plugin_info) {
   Version plugin_version;
   WebPluginInfo::CreateVersionFromString(plugin_info.version, &plugin_version);
@@ skipping 1291 matching lines @@
     case WM_RBUTTONUP:
       ::ReleaseCapture();
       break;
 
     default:
       break;
   }
 }
 
 }  // namespace content