Complete SyncMessageFilter initialization after SyncChannel initialization

ipc/ipc_channel_proxy.cc

Index: ipc/ipc_channel_proxy.cc
diff --git a/ipc/ipc_channel_proxy.cc b/ipc/ipc_channel_proxy.cc
index adb3d674ea3b82d8157ab615830a0b57baa053e6..2398b516419ac265c523863c13ad6ca0e696ef07 100644
--- a/ipc/ipc_channel_proxy.cc
+++ b/ipc/ipc_channel_proxy.cc
@@ -430,6 +430,7 @@ void ChannelProxy::Init(scoped_ptr<ChannelFactory> factory,
       FROM_HERE, base::Bind(&Context::OnChannelOpened, context_.get()));
 
   did_init_ = true;
+  OnChannelInit();
 }
 
 void ChannelProxy::Close() {
@@ -514,6 +515,9 @@ void ChannelProxy::SetAttachmentBrokerEndpoint(bool is_endpoint) {
   context()->set_attachment_broker_endpoint(is_endpoint);
 }
 
+void ChannelProxy::OnChannelInit() {
+}
+
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC