Remove calls to deprecated MessageLoop methods in ppapi.

ppapi/proxy/ppb_testing_proxy.cc

Index: ppapi/proxy/ppb_testing_proxy.cc
diff --git a/ppapi/proxy/ppb_testing_proxy.cc b/ppapi/proxy/ppb_testing_proxy.cc
index 6ddbd7ea801868233125c8fa4c8b301931bea14a..512bef9a4f87fb6b9fad41e144099e42b321ea2d 100644
--- a/ppapi/proxy/ppb_testing_proxy.cc
+++ b/ppapi/proxy/ppb_testing_proxy.cc
@@ -7,6 +7,7 @@
 #include <stddef.h>
 
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "ppapi/c/private/ppb_testing_private.h"
 #include "ppapi/proxy/enter_proxy.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
@@ -57,7 +58,7 @@ void RunMessageLoop(PP_Instance instance) {
       base::MessageLoop::current());
   CHECK(PpapiGlobals::Get()->GetMainThreadMessageLoop()->
       BelongsToCurrentThread());
-  base::MessageLoop::current()->Run();
+  base::RunLoop().Run();
 }
 
 void QuitMessageLoop(PP_Instance instance) {