A proposal and implementation for an initial postMessage interface. These in...

ppapi/cpp/instance.cc

Index: ppapi/cpp/instance.cc
===================================================================
--- ppapi/cpp/instance.cc	(revision 78988)
+++ ppapi/cpp/instance.cc	(working copy)
@@ -4,6 +4,7 @@
 
 #include "ppapi/cpp/instance.h"
 
+#include "ppapi/c/dev/ppb_messaging_dev.h"
 #include "ppapi/c/dev/ppp_printing_dev.h"
 #include "ppapi/c/ppb_instance.h"
 #include "ppapi/cpp/common.h"
@@ -25,6 +26,10 @@
   return PPB_INSTANCE_INTERFACE;
 }
 
+template <> const char* interface_name<PPB_Messaging_Dev>() {
+  return PPB_MESSAGING_DEV_INTERFACE;
+}
+
 }  // namespace
 
 Instance::Instance(PP_Instance instance) : pp_instance_(instance) {
@@ -61,6 +66,10 @@
   return false;
 }
 
+void Instance::HandleMessage(const Var& /*message_data*/) {
+  return;
+}
+
 Var Instance::GetInstanceObject() {
   return Var();
 }
@@ -115,6 +124,13 @@
                  Var::OutException(exception).get()));
 }
 
+void Instance::PostMessage(const Var& message) {
+  if (!has_interface<PPB_Messaging_Dev>())
+    return;
+  get_interface<PPB_Messaging_Dev>()->PostMessage(pp_instance(),
+                                                  message.pp_var());
+}
+
 void Instance::AddPerInstanceObject(const std::string& interface_name,
                                     void* object) {
   // Ensure we're not trying to register more than one object per interface