--- a/ipc/chromium/moz.build
+++ b/ipc/chromium/moz.build
@@ -30,17 +30,16 @@ UNIFIED_SOURCES += [
     'src/base/tracked_objects.cc',
     'src/chrome/common/child_process.cc',
     'src/chrome/common/child_process_host.cc',
     'src/chrome/common/child_process_info.cc',
     'src/chrome/common/child_thread.cc',
     'src/chrome/common/chrome_switches.cc',
     'src/chrome/common/ipc_channel.cc',
     'src/chrome/common/ipc_message.cc',
-    'src/chrome/common/message_router.cc',
     'src/chrome/common/notification_service.cc',
 ]
 
 if os_win:
     SOURCES += [
         'src/base/condition_variable_win.cc',
         'src/base/cpu.cc',
         'src/base/file_util_win.cc',

--- a/ipc/chromium/src/chrome/common/child_thread.cc
+++ b/ipc/chromium/src/chrome/common/child_thread.cc
@@ -57,33 +57,19 @@ bool ChildThread::Send(IPC::Message* msg
   if (!channel_.get()) {
     delete msg;
     return false;
   }
 
   return channel_->Send(msg);
 }
 
-void ChildThread::AddRoute(int32_t routing_id, IPC::Channel::Listener* listener) {
-  DCHECK(MessageLoop::current() == message_loop());
-
-  router_.AddRoute(routing_id, listener);
-}
-
-void ChildThread::RemoveRoute(int32_t routing_id) {
-  DCHECK(MessageLoop::current() == message_loop());
-
-  router_.RemoveRoute(routing_id);
-}
-
 void ChildThread::OnMessageReceived(const IPC::Message& msg) {
   if (msg.routing_id() == MSG_ROUTING_CONTROL) {
     OnControlMessageReceived(msg);
-  } else {
-    router_.OnMessageReceived(msg);
   }
 }
 
 ChildThread* ChildThread::current() {
   return ChildProcess::current()->child_thread();
 }
 
 void ChildThread::Init() {

--- a/ipc/chromium/src/chrome/common/child_thread.h
+++ b/ipc/chromium/src/chrome/common/child_thread.h
@@ -1,17 +1,17 @@
 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_CHILD_THREAD_H_
 #define CHROME_COMMON_CHILD_THREAD_H_
 
 #include "base/thread.h"
-#include "chrome/common/message_router.h"
+#include "chrome/common/ipc_channel.h"
 #include "mozilla/UniquePtr.h"
 
 class ResourceDispatcher;
 
 // Child processes's background thread should derive from this class.
 class ChildThread : public IPC::Channel::Listener,
                     public IPC::Message::Sender,
                     public base::Thread {
@@ -66,20 +66,16 @@ class ChildThread : public IPC::Channel:
 #endif
 
   // The message loop used to run tasks on the thread that started this thread.
   MessageLoop* owner_loop_;
 
   std::wstring channel_name_;
   mozilla::UniquePtr<IPC::Channel> channel_;
 
-  // Used only on the background render thread to implement message routing
-  // functionality to the consumers of the ChildThread.
-  MessageRouter router_;
-
   Thread::Options options_;
 
   // If true, checks with the browser process before shutdown.  This avoids race
   // conditions if the process refcount is 0 but there's an IPC message inflight
   // that would addref it.
   bool check_with_browser_before_shutdown_;
 
   DISALLOW_EVIL_CONSTRUCTORS(ChildThread);

deleted file mode 100644
--- a/ipc/chromium/src/chrome/common/message_router.cc
+++ /dev/null
@@ -1,42 +0,0 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/common/message_router.h"
-
-void MessageRouter::OnControlMessageReceived(const IPC::Message& msg) {
-  NOTREACHED() <<
-      "should override in subclass if you care about control messages";
-}
-
-bool MessageRouter::Send(IPC::Message* msg) {
-  NOTREACHED() <<
-      "should override in subclass if you care about sending messages";
-  return false;
-}
-
-void MessageRouter::AddRoute(int32_t routing_id,
-                             IPC::Channel::Listener* listener) {
-  routes_.AddWithID(listener, routing_id);
-}
-
-void MessageRouter::RemoveRoute(int32_t routing_id) {
-  routes_.Remove(routing_id);
-}
-
-void MessageRouter::OnMessageReceived(const IPC::Message& msg) {
-  if (msg.routing_id() == MSG_ROUTING_CONTROL) {
-    OnControlMessageReceived(msg);
-  } else {
-    RouteMessage(msg);
-  }
-}
-
-bool MessageRouter::RouteMessage(const IPC::Message& msg) {
-  IPC::Channel::Listener* listener = routes_.Lookup(msg.routing_id());
-  if (!listener)
-    return false;
-
-  listener->OnMessageReceived(msg);
-  return true;
-}

deleted file mode 100644
--- a/ipc/chromium/src/chrome/common/message_router.h
+++ /dev/null
@@ -1,60 +0,0 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_COMMON_MESSAGE_ROUTER_H__
-#define CHROME_COMMON_MESSAGE_ROUTER_H__
-
-#include "base/id_map.h"
-#include "chrome/common/ipc_channel.h"
-
-// The MessageRouter handles all incoming messages sent to it by routing them
-// to the correct listener.  Routing is based on the Message's routing ID.
-// Since routing IDs are typically assigned asynchronously by the browser
-// process, the MessageRouter has the notion of pending IDs for listeners that
-// have not yet been assigned a routing ID.
-//
-// When a message arrives, the routing ID is used to index the set of routes to
-// find a listener.  If a listener is found, then the message is passed to it.
-// Otherwise, the message is ignored if its routing ID is not equal to
-// MSG_ROUTING_CONTROL.
-//
-// The MessageRouter supports the IPC::Message::Sender interface for outgoing
-// messages, but does not define a meaningful implementation of it.  The
-// subclass of MessageRouter is intended to provide that if appropriate.
-//
-// The MessageRouter can be used as a concrete class provided its Send method
-// is not called and it does not receive any control messages.
-
-class MessageRouter : public IPC::Channel::Listener,
-                      public IPC::Message::Sender {
- public:
-  MessageRouter() {}
-  virtual ~MessageRouter() {}
-
-  // Implemented by subclasses to handle control messages
-  virtual void OnControlMessageReceived(const IPC::Message& msg);
-
-  // IPC::Channel::Listener implementation:
-  virtual void OnMessageReceived(const IPC::Message& msg);
-
-  // Like OnMessageReceived, except it only handles routed messages.  Returns
-  // true if the message was dispatched, or false if there was no listener for
-  // that route id.
-  virtual bool RouteMessage(const IPC::Message& msg);
-
-  // IPC::Message::Sender implementation:
-  virtual bool Send(IPC::Message* msg);
-
-  // Called to add/remove a listener for a particular message routing ID.
-  void AddRoute(int32_t routing_id, IPC::Channel::Listener* listener);
-  void RemoveRoute(int32_t routing_id);
-
- private:
-  // A list of all listeners with assigned routing IDs.
-  IDMap<IPC::Channel::Listener> routes_;
-
-  DISALLOW_EVIL_CONSTRUCTORS(MessageRouter);
-};
-
-#endif  // CHROME_COMMON_MESSAGE_ROUTER_H__