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

content/renderer/mouse_lock_dispatcher.cc

 // 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.
 
 #include "content/renderer/mouse_lock_dispatcher.h"
 
 #include "content/common/view_messages.h"
 #include "content/renderer/render_view_impl.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebWidget.h"
 
 MouseLockDispatcher::MouseLockDispatcher(RenderViewImpl* render_view_impl)
     : content::RenderViewObserver(render_view_impl),
       render_view_impl_(render_view_impl),
       mouse_locked_(false),
       pending_lock_request_(false),
       pending_unlock_request_(false),
       target_(NULL) {
 }
 
 MouseLockDispatcher::~MouseLockDispatcher() {
 }
 
 bool MouseLockDispatcher::LockMouse(LockTarget* target) {
   if (MouseLockedOrPendingAction())
     return false;
 
   pending_lock_request_ = true;
   target_ = target;
 
-  Send(new ViewHostMsg_LockMouse(routing_id()));
+  bool user_gesture =
+      render_view_impl_->webview() &&
+      render_view_impl_->webview()->mainFrame() &&
+      render_view_impl_->webview()->mainFrame()->isProcessingUserGesture();
+
+  Send(new ViewHostMsg_LockMouse(routing_id(), user_gesture));
   return true;
 }
 
 void MouseLockDispatcher::UnlockMouse(LockTarget* target) {
   if (target && target == target_ && !pending_unlock_request_) {
     pending_unlock_request_ = true;
     Send(new ViewHostMsg_UnlockMouse(routing_id()));
   }
 }
 
@@ skipping 66 matching lines @@
   LockTarget* last_target = target_;
   target_ = NULL;
 
   // Callbacks made after all state modification to prevent reentrant errors
   // such as OnMouseLockLost() synchronously calling LockMouse().
 
   if (last_target)
     last_target->OnMouseLockLost();
 }