Stub out initial NavigationController browser implementation

content/browser/nav_controller/nav_controller_dispatcher_host.cc

+// Copyright 2013 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 "content/browser/nav_controller/nav_controller_dispatcher_host.h"
+
+#include "content/browser/nav_controller/nav_controller_context.h"
+#include "content/common/nav_controller/nav_controller_messages.h"
+#include "ipc/ipc_message_macros.h"
+#include "url/gurl.h"
+
+namespace content {
+
+NavControllerDispatcherHost::NavControllerDispatcherHost(
+    NavControllerContext* context)
+    : context_(context) {}
+
+NavControllerDispatcherHost::~NavControllerDispatcherHost() {}
+
+bool NavControllerDispatcherHost::OnMessageReceived(const IPC::Message& message,
+                                                    bool* message_was_ok) {
+
+  if (IPC_MESSAGE_CLASS(message) != NavControllerMsgStart)
+    return false;
+
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP_EX(
+      NavControllerDispatcherHost, message, *message_was_ok)
+  IPC_MESSAGE_HANDLER(NavControllerHostMsg_RegisterController,
+                      OnRegisterController)
+  IPC_MESSAGE_HANDLER(NavControllerHostMsg_UnregisterController,
+                      OnUnregisterController)
+  IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+
+  return handled;
+}
+
+void NavControllerDispatcherHost::OnRegisterController(int32 host_id,
+                                                       const string16& scope,
+                                                       const GURL& script_url) {
+}
+
+void NavControllerDispatcherHost::OnUnregisterController(
+    int32 host_id,
+    const string16& scope) {}
+
+}  // namespace content