[Sync] Add size and crc32c to AttachmentId.

sync/internal_api/attachments/fake_attachment_downloader_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/fake_attachment_downloader.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "sync/api/attachments/attachment.h"
@@ skipping 32 matching lines @@
                     scoped_ptr<Attachment> attachment) {
     download_results_.push_back(result);
   }
 
   base::MessageLoop message_loop_;
   FakeAttachmentDownloader attachment_downloader_;
   std::vector<AttachmentDownloader::DownloadResult> download_results_;
 };
 
 TEST_F(FakeAttachmentDownloaderTest, DownloadAttachment) {
-  AttachmentId attachment_id = AttachmentId::Create();
+  AttachmentId attachment_id = AttachmentId::Create(0, 0);
   downloader()->DownloadAttachment(attachment_id, download_callback());
   RunMessageLoop();
   EXPECT_EQ(1U, download_results().size());
   EXPECT_EQ(AttachmentDownloader::DOWNLOAD_SUCCESS, download_results()[0]);
 }
 
 }  // namespace syncer