Never lock the Pepper proxy lock on the IO thread

ppapi/proxy/plugin_globals.cc

Index: ppapi/proxy/plugin_globals.cc
diff --git a/ppapi/proxy/plugin_globals.cc b/ppapi/proxy/plugin_globals.cc
index 6bb9c75860aca4bf94d8be21b6c98de48e8a2911..25db64e97c17e4e024497836bfaa450c3d17fcfc 100644
--- a/ppapi/proxy/plugin_globals.cc
+++ b/ppapi/proxy/plugin_globals.cc
@@ -9,10 +9,12 @@
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_sender.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
+#include "ppapi/proxy/plugin_message_filter.h"
 #include "ppapi/proxy/plugin_proxy_delegate.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/ppb_message_loop_proxy.h"
 #include "ppapi/proxy/resource_reply_thread_registrar.h"
+#include "ppapi/proxy/udp_socket_filter.h"
 #include "ppapi/shared_impl/ppapi_constants.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/thunk/enter.h"
@@ -57,6 +59,7 @@ PluginGlobals::PluginGlobals()
       callback_tracker_(new CallbackTracker),
       resource_reply_thread_registrar_(
           new ResourceReplyThreadRegistrar(GetMainThreadMessageLoop())),
+      udp_socket_filter_(new UDPSocketFilter()),
       plugin_recently_active_(false),
       keepalive_throttle_interval_milliseconds_(
           ppapi::kKeepaliveThrottleIntervalDefaultMilliseconds),
@@ -236,6 +239,11 @@ MessageLoopResource* PluginGlobals::loop_for_main_thread() {
   return loop_for_main_thread_.get();
 }
 
+void PluginGlobals::RegisterResourceMessageFilters(
+      ppapi::proxy::PluginMessageFilter* plugin_filter) {
+  plugin_filter->AddResourceMessageFilter(udp_socket_filter_.get());
+}
+
 void PluginGlobals::set_keepalive_throttle_interval_milliseconds(unsigned i) {
   keepalive_throttle_interval_milliseconds_ = i;
 }