Fix include path for moved thread_task_runner_handle.h header in sync/

sync/internal_api/attachments/on_disk_attachment_store_unittest.cc

 // Copyright 2014 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 "sync/internal_api/public/attachments/on_disk_attachment_store.h"
 
 #include <stdint.h>
 
 #include <string>
 #include <utility>
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
-#include "base/thread_task_runner_handle.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "sync/internal_api/attachments/attachment_store_test_template.h"
 #include "sync/internal_api/attachments/proto/attachment_store.pb.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/leveldatabase/src/include/leveldb/db.h"
 #include "third_party/leveldatabase/src/include/leveldb/options.h"
 #include "third_party/leveldatabase/src/include/leveldb/slice.h"
 #include "third_party/leveldatabase/src/include/leveldb/status.h"
 
@@ skipping 486 matching lines @@
   store_->ReadMetadata(
       base::Bind(&OnDiskAttachmentStoreSpecificTest::CopyResultMetadata,
                  base::Unretained(this), &metadata_result, &metadata_list));
   RunLoop();
   EXPECT_EQ(AttachmentStore::SUCCESS, create_result);
   EXPECT_EQ(AttachmentStore::UNSPECIFIED_ERROR, metadata_result);
   EXPECT_EQ(2U, metadata_list->size());
 }
 
 }  // namespace syncer