Update sync API to support attachments.

sync/api/attachments/attachment_service_proxy.cc

Index: sync/api/attachments/attachment_service_proxy.cc
diff --git a/sync/api/attachments/attachment_service_proxy.cc b/sync/api/attachments/attachment_service_proxy.cc
new file mode 100644
index 0000000000000000000000000000000000000000..065f467b54688c60edf42effc0494320285fe03a
--- /dev/null
+++ b/sync/api/attachments/attachment_service_proxy.cc
@@ -0,0 +1,103 @@
+// 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/api/attachments/attachment_service_proxy.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "sync/api/sync_data.h"
+
+namespace syncer {
+
+namespace {
+
+// These ProxyFooCallback functions are used to invoke a callback in a specific
+// thread.
+
+// Invokes |callback| with |result| and |attachments| in the |task_runner|
+// thread.
+void ProxyGetOrDownloadCallback(
+    const scoped_refptr<base::SequencedTaskRunner>& task_runner,
+    const AttachmentService::GetOrDownloadCallback& callback,
+    const AttachmentService::GetOrDownloadResult& result,
+    const AttachmentMap& attachments) {
+  task_runner->PostTask(FROM_HERE, base::Bind(callback, result, attachments));
+}
+
+// Invokes |callback| with |result| and |attachments| in the |task_runner|
+// thread.
+void ProxyDropCallback(
+    const scoped_refptr<base::SequencedTaskRunner>& task_runner,
+    const AttachmentService::DropCallback& callback,
+    const AttachmentService::DropResult& result) {
+  task_runner->PostTask(FROM_HERE, base::Bind(callback, result));
+}
+
+}  // namespace
+
+AttachmentServiceProxy::AttachmentServiceProxy() {}
+
+AttachmentServiceProxy::AttachmentServiceProxy(
+    const scoped_refptr<base::SequencedTaskRunner>& wrapped_task_runner,
+    base::WeakPtr<syncer::AttachmentService> wrapped)
+    : wrapped_task_runner_(wrapped_task_runner), wrapped_(wrapped) {
+  DCHECK(wrapped_task_runner_);
+}
+
+AttachmentServiceProxy::~AttachmentServiceProxy() {}
+
+void AttachmentServiceProxy::GetOrDownloadAttachments(
+    const AttachmentIdList& attachment_ids,
+    const GetOrDownloadCallback& callback) {
+  DCHECK(wrapped_task_runner_);
+  GetOrDownloadCallback proxy_callback = base::Bind(
+      &ProxyGetOrDownloadCallback, base::MessageLoopProxy::current(), callback);
+  wrapped_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&AttachmentService::GetOrDownloadAttachments,
+                 wrapped_,
+                 attachment_ids,
+                 proxy_callback));
+}
+
+void AttachmentServiceProxy::DropAttachments(
+    const AttachmentIdList& attachment_ids,
+    const DropCallback& callback) {
+  DCHECK(wrapped_task_runner_);
+  DropCallback proxy_callback = base::Bind(
+      &ProxyDropCallback, base::MessageLoopProxy::current(), callback);
+  wrapped_task_runner_->PostTask(FROM_HERE,
+                                 base::Bind(&AttachmentService::DropAttachments,
+                                            wrapped_,
+                                            attachment_ids,
+                                            proxy_callback));
+}
+
+void AttachmentServiceProxy::OnSyncDataAdd(const SyncData& sync_data) {
+  DCHECK(wrapped_task_runner_);
+  wrapped_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&AttachmentService::OnSyncDataAdd, wrapped_, sync_data));
+}
+
+void AttachmentServiceProxy::OnSyncDataDelete(const SyncData& sync_data) {
+  DCHECK(wrapped_task_runner_);
+  wrapped_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&AttachmentService::OnSyncDataDelete, wrapped_, sync_data));
+}
+
+void AttachmentServiceProxy::OnSyncDataUpdate(
+    const AttachmentIdList& old_attachment_ids,
+    const SyncData& updated_sync_data) {
+  DCHECK(wrapped_task_runner_);
+  wrapped_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&AttachmentService::OnSyncDataUpdate,
+                 wrapped_,
+                 old_attachment_ids,
+                 updated_sync_data));
+}
+
+}  // namespace syncer