(NOT READY FOR REVIEW) Introduce MessagePortBypassFilter.

content/child/child_thread.cc

Index: content/child/child_thread.cc
diff --git a/content/child/child_thread.cc b/content/child/child_thread.cc
index 3ecdb584d8e5b3af784ac98a45eeb9aa531daab0..e549023114e643d1bac601c074058e2042fa2f0b 100644
--- a/content/child/child_thread.cc
+++ b/content/child/child_thread.cc
@@ -13,6 +13,7 @@
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/debug/leak_annotations.h"
+#include "base/id_map.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ -39,6 +40,7 @@
 #include "content/child/thread_safe_sender.h"
 #include "content/child/websocket_dispatcher.h"
 #include "content/common/child_process_messages.h"
+#include "content/common/message_port_messages.h"
 #include "content/public/common/content_switches.h"
 #include "ipc/ipc_logging.h"
 #include "ipc/ipc_switches.h"
@@ -193,6 +195,62 @@ void QuitMainThreadMessageLoop() {
 
 }  // namespace
 
+MessagePortBypassFilter::MessagePortBypassFilter(
+    base::SingleThreadTaskRunner* ipc_task_runner)
+    : ipc_task_runner_(ipc_task_runner),
+      child_thread_loop_(base::MessageLoopProxy::current()) {}
+
+MessagePortBypassFilter::~MessagePortBypassFilter() {}
+
+bool MessagePortBypassFilter::OnMessageReceived(const IPC::Message& message) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  IPC::Listener* listener = routes_.Lookup(message.routing_id());
+  if (!listener)
+    return false;
+  if (message.type() != MessagePortMsg_Message::ID)
+    return false;
+  return listener->OnMessageReceived(message);
+}
+
+bool MessagePortBypassFilter::GetSupportedMessageClasses(
+    std::vector<uint32>* supported_message_classes) const {
+  supported_message_classes->push_back(MessagePortMsgStart);
+  return true;
+}
+
+void MessagePortBypassFilter::AddRoute(int32 routing_id,
+                                       IPC::Listener* listener) {
+  DCHECK(child_thread_loop_->BelongsToCurrentThread());
+  ipc_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &MessagePortBypassFilter::AddRouteOnIO, this, routing_id, listener));
+}
+
+void MessagePortBypassFilter::AddRouteOnIO(int32 routing_id,
+                                           IPC::Listener* listener) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  routes_.AddWithID(listener, routing_id);
+}
+
+void MessagePortBypassFilter::RemoveRoute(int32 routing_id,
+                                          const base::Closure& callback) {
+  DCHECK(child_thread_loop_->BelongsToCurrentThread());
+  ipc_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&MessagePortBypassFilter::RemoveRouteOnIO,
+                 this,
+                 routing_id,
+                 callback));
+}
+
+void MessagePortBypassFilter::RemoveRouteOnIO(int32 routing_id,
+                                              const base::Closure& callback) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  routes_.Remove(routing_id);
+  child_thread_loop_->PostTask(FROM_HERE, callback);
+}
+
 ChildThread::ChildThreadMessageRouter::ChildThreadMessageRouter(
     IPC::Sender* sender)
     : sender_(sender) {}
@@ -263,6 +321,8 @@ void ChildThread::Init() {
       new QuotaMessageFilter(thread_safe_sender_.get());
   quota_dispatcher_.reset(new QuotaDispatcher(thread_safe_sender_.get(),
                                               quota_message_filter_.get()));
+  message_port_bypass_filter_ = new MessagePortBypassFilter(
+      ChildProcess::current()->io_message_loop_proxy());
 
   channel_->AddFilter(histogram_message_filter_.get());
   channel_->AddFilter(sync_message_filter_.get());
@@ -271,6 +331,7 @@ void ChildThread::Init() {
   channel_->AddFilter(resource_message_filter_.get());
   channel_->AddFilter(quota_message_filter_->GetFilter());
   channel_->AddFilter(service_worker_message_filter_->GetFilter());
+  channel_->AddFilter(message_port_bypass_filter_.get());
 
   // In single process mode we may already have a power monitor
   if (!base::PowerMonitor::Get()) {