Add means for running some tests only o-o-p, add messaging o-o-p test.

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 ab069b11cce154583aa6959266a90bf22d860d1b..f2ce6b290976a3b8d59cd0ca5a40f6fb50217ff3 100644
--- a/ppapi/proxy/ppb_testing_proxy.cc
+++ b/ppapi/proxy/ppb_testing_proxy.cc
@@ -63,11 +63,16 @@ uint32_t GetLiveObjectsForInstance(PP_Instance instance_id) {
   return result;
 }
 
+PP_Bool IsOutOfProcess() {
+  return PP_TRUE;
+}
+
 const PPB_Testing_Dev testing_interface = {
   &ReadImageData,
   &RunMessageLoop,
   &QuitMessageLoop,
-  &GetLiveObjectsForInstance
+  &GetLiveObjectsForInstance,
+  &IsOutOfProcess
 };
 
 InterfaceProxy* CreateTestingProxy(Dispatcher* dispatcher,