Stub out initial NavigationController browser implementation

content/common/nav_controller/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
+
+IPC_MESSAGE_CONTROL3(NavControllerHostMsg_RegisterController,

[michaeln, 2013/09/09 20:55:49]

Since you're defining messages that require a 'peer_id' parameter in this CL, it
might make sense to also define the two messages to create/delete the 'peer'
itself (analogs of AppCacheHostMsg_RegisterHost and
AppCacheHostMsg_UnRegisterHost).

For lack of a better name referring to this as the NavControllerPeer seems ok?
NavControllerHostMsg_CreatePeer(int peer_id);
NavControllerHostMsg_DeletePeer(int peer_id);

In anticipation of adding some c++ classes on either end in later CLs...
class NavControllerPeer // browser process c++ class
-----
class WebNavControllerPeer // WebKitAPI defined interface
class WebNavControllerPeerImpl // client process c++ class that impls the
WebKitAPI interface

[alecflett, 2013/09/12 21:04:56]

The peer is just a temporary object that exists in the renderer during
registration - it is 'created' when RegisterController() is called, and likely
destroyed (working out details there) after the
NavControllerMsg_ControllerRegistered message comes through.

+                     int32 /* peer_id */,
+                     string16 /* scope */,
+                     GURL /* script_url */)
+
+IPC_MESSAGE_CONTROL1(NavControllerMsg_ControllerReady, int32 /* peer_id */)
+
+IPC_MESSAGE_CONTROL2(NavControllerHostMsg_UnregisterController,
+                     int32 /* peer_id */,
+                     string16 /* scope */)
+
+IPC_MESSAGE_CONTROL2(NavControllerMsg_ControllerUnregistered,
+                     int32 /* peer_id */,
+                     string16 /* scope */)