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

ppapi/proxy/plugin_proxy_delegate.h

Index: ppapi/proxy/plugin_proxy_delegate.h
diff --git a/ppapi/proxy/plugin_proxy_delegate.h b/ppapi/proxy/plugin_proxy_delegate.h
index 5045ba722beacd8f6ed54255e1ac6c7fdf4a0e75..0d1807a1eeec0d3980e31e9ddab9d20647fc018f 100644
--- a/ppapi/proxy/plugin_proxy_delegate.h
+++ b/ppapi/proxy/plugin_proxy_delegate.h
@@ -5,6 +5,8 @@
 #ifndef PPAPI_PROXY_PLUGIN_PROXY_DELEGATE_H_
 #define PPAPI_PROXY_PLUGIN_PROXY_DELEGATE_H_
 
+#include <string>
+
 namespace ppapi {
 namespace proxy {
 
@@ -16,6 +18,9 @@ class PPAPI_PROXY_EXPORT PluginProxyDelegate {
   // 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;