Propogate the UI language on the command line and expose to Flash.

ppapi/proxy/plugin_proxy_delegate.h

 // Copyright (c) 2011 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.
 
 #ifndef PPAPI_PROXY_PLUGIN_PROXY_DELEGATE_H_
 #define PPAPI_PROXY_PLUGIN_PROXY_DELEGATE_H_
 
+#include <string>
+
 namespace ppapi {
 namespace proxy {
 
 class PPAPI_PROXY_EXPORT PluginProxyDelegate {
  public:
   virtual ~PluginProxyDelegate() {}
 
   // Sends the given message to the browser. Identical semantics to
   // IPC::Message::Sender interface.
   virtual bool SendToBrowser(IPC::Message* msg) = 0;
 
+  // Returns the language code of the current UI language.
+  virtual std::string GetUILanguage() = 0;
+
   // Performs Windows-specific font caching in the browser for the given
   // LOGFONTW. Does nothing on non-Windows platforms.
   virtual void PreCacheFont(const void* logfontw) = 0;
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PLUGIN_PROXY_DELEGATE_H_