Added a ResourceMessageFilter for handling resource messages on another thread.

ppapi/host/ppapi_host.cc

Index: ppapi/host/ppapi_host.cc
diff --git a/ppapi/host/ppapi_host.cc b/ppapi/host/ppapi_host.cc
index 44d3ee5d390149618a2fb105e6cd3b213aba3f11..05d75c02d762a106980b3c8f4a8f885c3e0f52d6 100644
--- a/ppapi/host/ppapi_host.cc
+++ b/ppapi/host/ppapi_host.cc
@@ -118,40 +118,14 @@ void PpapiHost::HandleResourceCall(
     const proxy::ResourceMessageCallParams& params,
     const IPC::Message& nested_msg,
     HostMessageContext* context) {
-  ReplyMessageContext reply_context = context->MakeReplyMessageContext();
-
   ResourceHost* resource_host = GetResourceHost(params.pp_resource());
   if (resource_host) {
-    reply_context.params.set_result(
-        resource_host->OnResourceMessageReceived(nested_msg, context));
-
-    // Sanity check the resource handler. Note if the result was
-    // "completion pending" the resource host may have already sent the reply.
-    if (reply_context.params.result() == PP_OK_COMPLETIONPENDING) {
-      // Message handler should have only returned a pending result if a
-      // response will be sent to the plugin.
-      DCHECK(params.has_callback());
-
-      // Message handler should not have written a message to be returned if
-      // completion is pending.
-      DCHECK(context->reply_msg.type() == 0);
-    } else if (!params.has_callback()) {
-      // When no response is required, the message handler should not have
-      // written a message to be returned.
-      DCHECK(context->reply_msg.type() == 0);
-
-      // If there is no callback and the result of running the message handler
-      // was not PP_OK the client won't find out.
-      DLOG_IF(WARNING, reply_context.params.result() != PP_OK)
-          << "'Post' message handler failed to complete successfully.";
-    }
+    resource_host->HandleMessage(nested_msg, context);
   } else {
+    ReplyMessageContext reply_context = context->MakeReplyMessageContext();
     reply_context.params.set_result(PP_ERROR_BADRESOURCE);
-  }
-
-  if (params.has_callback() &&
-      reply_context.params.result() != PP_OK_COMPLETIONPENDING)
     SendReply(reply_context, context->reply_msg);

[yzshen1, 2012/11/13 21:51:48]

Maybe the message doesn't expect a reply.

[raymes, 2012/11/16 18:56:35]

Done.

+  }
 }
 
 void PpapiHost::OnHostMsgResourceCreated(