DO NOT REVIEW Plumb push messaging registration through to gcm.

content/common/push_messaging_messages.h

+// Copyright 2014 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.
+
+// IPC messages for push messaging.
+// Multiply-included message file, hence no include guard.
+
+#include "content/public/common/push_messaging_status.h"
+#include "ipc/ipc_message_macros.h"
+
+#define IPC_MESSAGE_START PushMessagingMsgStart
+
+IPC_ENUM_TRAITS_MAX_VALUE(content::PushMessagingStatus,
+                          content::PUSH_MESSAGING_STATUS_UNKNOWN_ERROR)
+
+// Messages sent from the browser to the renderer.
+
+IPC_MESSAGE_ROUTED4(PushMessagingMsg_RegisterSuccess,
+                    int32 /* callbacks_id */,
+                    std::string /* endpoint */,
+                    std::string /* registration_id */,
+                    std::string /* channel_name */)
+
+IPC_MESSAGE_ROUTED2(PushMessagingMsg_RegisterError,
+                    int32 /* callbacks_id */,
+                    content::PushMessagingStatus /* status */)
+
+// Messages sent from the renderer to the browser.
+
+IPC_MESSAGE_CONTROL3(PushMessagingHostMsg_Register,
+                     int32 /* routing_id */,
+                     int32 /* callbacks_id */,
+                     std::string /* channel_name */)