Stub out initial NavigationController browser implementation

content/common/nav_controller_messages.h

+// Copyright (c) 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.
+
+// Message definition file, included multiple times, hence no include guard.
+
+#include "base/strings/string16.h"
+#include "ipc/ipc_message_macros.h"
+#include "ipc/ipc_param_traits.h"
+#include "url/gurl.h"
+
+#define IPC_MESSAGE_START NavControllerMsgStart
+
+// Messages sent from the child process to the browser.
+
+IPC_MESSAGE_CONTROL3(NavControllerHostMsg_RegisterController,
+                     int32 /* callback_id */,
+                     string16 /* scope */,
+                     GURL /* script_url */)
+
+IPC_MESSAGE_CONTROL2(NavControllerHostMsg_UnregisterController,
+                     int32 /* callback_id */,
+                     string16 /* scope (url pattern) */)
+
+// Messages sent from the browser to the child process.
+
+// Response to NavControllerMsg_RegisterController
+IPC_MESSAGE_CONTROL1(NavControllerMsg_ControllerRegistered,
+                     int32 /* callback_id */)
+
+// Response to NavControllerMsg_UnregisterController
+IPC_MESSAGE_CONTROL2(NavControllerMsg_ControllerUnregistered,
+                     int32 /* callback_id */)