PPAPI: Make blocking completion callbacks work.

ppapi/thunk/ppb_mouse_lock_thunk.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 "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_mouse_lock.h"
+#include "ppapi/shared_impl/tracked_callback.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_instance_api.h"
 #include "ppapi/thunk/thunk.h"
 
 namespace ppapi {
 namespace thunk {
 
 namespace {
 
 int32_t LockMouse(PP_Instance instance, PP_CompletionCallback callback) {
   EnterInstance enter(instance, callback);
   if (enter.failed())
     return enter.retval();
-  return enter.SetResult(enter.functions()->LockMouse(instance, callback));
+  return enter.SetResult(enter.functions()->LockMouse(instance,
+                                                      enter.callback()));
 }
 
 void UnlockMouse(PP_Instance instance) {
   EnterInstance enter(instance);
   if (enter.failed())
     return;
   enter.functions()->UnlockMouse(instance);
 }
 
 const PPB_MouseLock g_ppb_mouse_lock_thunk = {
   &LockMouse,
   &UnlockMouse
 };
 
 }  // namespace
 
 const PPB_MouseLock_1_0* GetPPB_MouseLock_1_0_Thunk() {
   return &g_ppb_mouse_lock_thunk;
 }
 
 }  // namespace thunk
 }  // namespace ppapi