Introduce lock screen app context to extension features

extensions/common/extension_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 extensions.
 // Multiply-included message file, hence no include guard.
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 621 matching lines @@
                     extensions::PortId /* target_port_id */,
                     extensions::Message)
 
 // Dispatch the Port.onDisconnect event for message channels.
 IPC_MESSAGE_ROUTED2(ExtensionMsg_DispatchOnDisconnect,
                     extensions::PortId /* port_id */,
                     std::string /* error_message */)
 
 // Informs the renderer what channel (dev, beta, stable, etc) and user session
 // type is running.
-IPC_MESSAGE_CONTROL2(ExtensionMsg_SetSessionInfo,
+IPC_MESSAGE_CONTROL3(ExtensionMsg_SetSessionInfo,
                      version_info::Channel /* channel */,
-                     extensions::FeatureSessionType /* session_type */)
+                     extensions::FeatureSessionType /* session_type */,
+                     bool /* is_lock_screen_context */)
 
 // Notify the renderer that its window has closed.
 IPC_MESSAGE_ROUTED0(ExtensionMsg_AppWindowClosed)
 
 // Notify the renderer that an extension wants notifications when certain
 // searches match the active page.  This message replaces the old set of
 // searches, and triggers ExtensionHostMsg_OnWatchedPageChange messages from
 // each tab to keep the browser updated about changes.
 IPC_MESSAGE_CONTROL1(ExtensionMsg_WatchPages,
                      std::vector<std::string> /* CSS selectors */)
@@ skipping 280 matching lines @@
                      int64_t /* service_worker_version_id */,
                      std::string /* request_uuid */)
 
 // Asks the browser to decrement the pending activity count for
 // the worker with version id |service_worker_version_id|.
 // |request_uuid| must match the GUID of a previous request, otherwise the
 // browser process ignores the IPC.
 IPC_MESSAGE_CONTROL2(ExtensionHostMsg_DecrementServiceWorkerActivity,
                      int64_t /* service_worker_version_id */,
                      std::string /* request_uuid */)