Add a new globals object for PPAPI tracking information.

ppapi/proxy/ppp_messaging_proxy.cc

Index: ppapi/proxy/ppp_messaging_proxy.cc
diff --git a/ppapi/proxy/ppp_messaging_proxy.cc b/ppapi/proxy/ppp_messaging_proxy.cc
index 390794a8d237979f62294c1584af725a8e60b896..60cd8c4ef526632eaee4f56090d1913b89823154 100644
--- a/ppapi/proxy/ppp_messaging_proxy.cc
+++ b/ppapi/proxy/ppp_messaging_proxy.cc
@@ -12,6 +12,8 @@
 #include "ppapi/proxy/plugin_var_tracker.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/serialized_var.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/var_tracker.h"
 
 namespace ppapi {
 namespace proxy {
@@ -82,7 +84,7 @@ void PPP_Messaging_Proxy::OnMsgHandleMessage(
   PP_Var received_var(message_data.Get(dispatcher()));
   // SerializedVarReceiveInput will decrement the reference count, but we want
   // to give the recipient a reference.
-  PluginResourceTracker::GetInstance()->var_tracker().AddRefVar(received_var);
+  PpapiGlobals::Get()->GetVarTracker()->AddRefVar(received_var);
   ppp_messaging_impl_->HandleMessage(instance, received_var);
 }