PPAPI: Make blocking completion callbacks work.

webkit/plugins/ppapi/ppb_directory_reader_impl.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 "webkit/plugins/ppapi/ppb_directory_reader_impl.h"
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/dev/ppb_directory_reader_dev.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 #include "ppapi/shared_impl/resource_tracker.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_file_ref_api.h"
 #include "webkit/plugins/ppapi/common.h"
 #include "webkit/plugins/ppapi/file_callbacks.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 #include "webkit/plugins/ppapi/plugin_module.h"
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/ppb_file_ref_impl.h"
 #include "webkit/plugins/ppapi/ppb_file_system_impl.h"
 #include "webkit/plugins/ppapi/resource_helper.h"
 
 using ::ppapi::PpapiGlobals;
+using ::ppapi::TrackedCallback;
 using ::ppapi::thunk::EnterResourceNoLock;
 using ::ppapi::thunk::PPB_DirectoryReader_API;
 using ::ppapi::thunk::PPB_FileRef_API;
 
 namespace webkit {
 namespace ppapi {
 
 namespace {
 
 std::string FilePathStringToUTF8String(const FilePath::StringType& str) {
@@ skipping 37 matching lines @@
   return (new PPB_DirectoryReader_Impl(
       static_cast<PPB_FileRef_Impl*>(enter.object())))->GetReference();
 }
 
 PPB_DirectoryReader_API* PPB_DirectoryReader_Impl::AsPPB_DirectoryReader_API() {
   return this;
 }
 
 int32_t PPB_DirectoryReader_Impl::GetNextEntry(
     PP_DirectoryEntry_Dev* entry,
-    PP_CompletionCallback callback) {
-  if (!callback.func)
-    return PP_ERROR_BLOCKS_MAIN_THREAD;
+    scoped_refptr<TrackedCallback> callback) {
   if (directory_ref_->GetFileSystemType() == PP_FILESYSTEMTYPE_EXTERNAL)
     return PP_ERROR_FAILED;
 
   entry_ = entry;
   if (FillUpEntry()) {
     entry_ = NULL;
     return PP_OK;
   }
   PluginInstance* plugin_instance = ResourceHelper::GetPluginInstance(this);
   if (!plugin_instance)
@@ skipping 52 matching lines @@
   if (!has_more_) {
     entry_->file_ref = 0;
     return true;
   }
 
   return false;
 }
 
 }  // namespace ppapi
 }  // namespace webkit