User Gesture plumbed from Renderer to Browser's FullscreenController::RequestToLockMouse.

content/common/view_messages.h

 // Copyright (c) 2012 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 page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "content/common/content_export.h"
@@ skipping 1975 matching lines @@
                     GURL /* frame's url */,
                     std::string /* data buffer */,
                     int32 /* complete status */)
 
 // Notifies the browser of an event occurring in the media pipeline.
 IPC_MESSAGE_CONTROL1(ViewHostMsg_MediaLogEvent,
                      media::MediaLogEvent /* event */)
 
 // Requests to lock the mouse. Will result in a ViewMsg_LockMouse_ACK message
 // being sent back.
-IPC_MESSAGE_ROUTED0(ViewHostMsg_LockMouse)
+IPC_MESSAGE_ROUTED1(ViewHostMsg_LockMouse,
+                    bool /* user_gesture */)
 
 // Requests to unlock the mouse. A ViewMsg_MouseLockLost message will be sent
 // whenever the mouse is unlocked (which may or may not be caused by
 // ViewHostMsg_UnlockMouse).
 IPC_MESSAGE_ROUTED0(ViewHostMsg_UnlockMouse)
 
 // Following message is used to communicate the values received by the
 // callback binding the JS to Cpp.
 // An instance of browser that has an automation host listening to it can
 // have a javascript send a native value (string, number, boolean) to the
 // listener in Cpp. (DomAutomationController)
 IPC_MESSAGE_ROUTED2(ViewHostMsg_DomOperationResponse,
                     std::string  /* json_string */,
                     int  /* automation_id */)
 
 // Sent to the browser when the renderer detects it is blocked on a pepper
 // plugin message for too long. This is also sent when it becomes unhung
 // (according to the value of is_hung). The browser can give the user the
 // option of killing the plugin.
 IPC_MESSAGE_ROUTED3(ViewHostMsg_PepperPluginHung,
                     int /* plugin_child_id */,
                     FilePath /* path */,
                     bool /* is_hung */)