(NOT READY FOR REVIEW) Introduce MessagePortBypassFilter.

content/child/webmessageportchannel_impl.cc

Index: content/child/webmessageportchannel_impl.cc
diff --git a/content/child/webmessageportchannel_impl.cc b/content/child/webmessageportchannel_impl.cc
index cf439cc0742851de8270d70f228bf20b1e86f20c..808bda5869ca363e417af0796ed2b5f1712db2d3 100644
--- a/content/child/webmessageportchannel_impl.cc
+++ b/content/child/webmessageportchannel_impl.cc
@@ -65,9 +65,24 @@ void WebMessagePortChannelImpl::setClient(WebMessagePortChannelClient* client) {
   client_ = client;
 }
 
+void WebMessagePortChannelImpl::OnRouteRemoved() {
+  child_thread_loop_->ReleaseSoon(FROM_HERE, this);
+}
+
 void WebMessagePortChannelImpl::destroy() {
+  if (!child_thread_loop_->BelongsToCurrentThread()) {
+    child_thread_loop_->PostTask(
+        FROM_HERE, base::Bind(&WebMessagePortChannelImpl::destroy, this));
+    return;
+  }
   setClient(NULL);
 
+  if (route_id_ != MSG_ROUTING_NONE) {
+    ChildThread::current()->message_port_bypass_filter()->RemoveRoute(
+        route_id_,
+        base::Bind(&WebMessagePortChannelImpl::OnRouteRemoved, this));
+    return;
+  }
   // Release the object on the main thread, since the destructor might want to
   // send an IPC, and that has to happen on the main thread.
   child_thread_loop_->ReleaseSoon(FROM_HERE, this);
@@ -149,6 +164,8 @@ void WebMessagePortChannelImpl::Init() {
         &route_id_, &message_port_id_));
   }
 
+  ChildThread::current()->message_port_bypass_filter()->AddRoute(route_id_,
+                                                                 this);
   ChildThread::current()->GetRouter()->AddRoute(route_id_, this);
 }