PPAPI: Make blocking completion callbacks work.

ppapi/proxy/ppb_instance_proxy.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/proxy/ppb_instance_proxy.h"
 
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/pp_time.h"
 #include "ppapi/c/pp_var.h"
 #include "ppapi/c/ppb_audio_config.h"
@@ skipping 418 matching lines @@
     image_host_resource = cursor_image->host_resource();
   }
 
   dispatcher()->Send(new PpapiHostMsg_PPBInstance_SetCursor(
       API_ID_PPB_INSTANCE, instance, static_cast<int32_t>(type),
       image_host_resource, hot_spot ? *hot_spot : PP_MakePoint(0, 0)));
   return PP_TRUE;
 }
 
 int32_t PPB_Instance_Proxy::LockMouse(PP_Instance instance,
-                                      PP_CompletionCallback callback) {
-  if (!callback.func)
-    return PP_ERROR_BADARGUMENT;
-
+                                      ApiCallbackType callback) {
   // Save the mouse callback on the instance data.
   InstanceData* data = static_cast<PluginDispatcher*>(dispatcher())->
       GetInstanceData(instance);
   if (!data)
     return PP_ERROR_BADARGUMENT;
-  if (data->mouse_lock_callback.func)
+  if (TrackedCallback::IsPending(data->mouse_lock_callback))
     return PP_ERROR_INPROGRESS;  // Already have a pending callback.
   data->mouse_lock_callback = callback;
 
   dispatcher()->Send(new PpapiHostMsg_PPBInstance_LockMouse(
       API_ID_PPB_INSTANCE, instance));
   return PP_OK_COMPLETIONPENDING;
 }
 
 void PPB_Instance_Proxy::UnlockMouse(PP_Instance instance) {
   dispatcher()->Send(new PpapiHostMsg_PPBInstance_UnlockMouse(
@@ skipping 225 matching lines @@
   }
 }
 
 void PPB_Instance_Proxy::OnPluginMsgMouseLockComplete(PP_Instance instance,
                                                       int32_t result) {
   // Save the mouse callback on the instance data.
   InstanceData* data = static_cast<PluginDispatcher*>(dispatcher())->
       GetInstanceData(instance);
   if (!data)
     return;  // Instance was probably deleted.
-  if (!data->mouse_lock_callback.func) {
+  if (TrackedCallback::IsPending(data->mouse_lock_callback)) {
     NOTREACHED();
     return;
   }
-  PP_RunAndClearCompletionCallback(&data->mouse_lock_callback, result);
+  TrackedCallback::ClearAndRun(&(data->mouse_lock_callback), result);
 }
 
 void PPB_Instance_Proxy::MouseLockCompleteInHost(int32_t result,
                                                  PP_Instance instance) {
   dispatcher()->Send(new PpapiMsg_PPBInstance_MouseLockComplete(
       API_ID_PPB_INSTANCE, instance, result));
 }
 
 }  // namespace proxy
 }  // namespace ppapi