Add a minimal AttachmentUploaderImpl.

sync/internal_api/public/attachments/attachment_uploader_impl.h

Index: sync/internal_api/public/attachments/attachment_uploader_impl.h
diff --git a/sync/internal_api/public/attachments/attachment_uploader_impl.h b/sync/internal_api/public/attachments/attachment_uploader_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..0720bcb0594334e7da082471f5e90334030e58e4
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+++ b/sync/internal_api/public/attachments/attachment_uploader_impl.h
@@ -0,0 +1,52 @@
+// 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.
+
+#ifndef SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_UPLOADER_IMPL_H_
+#define SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_UPLOADER_IMPL_H_
+
+#include "base/containers/scoped_ptr_hash_map.h"
+#include "base/threading/non_thread_safe.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "sync/api/attachments/attachment_uploader.h"
+
+class GURL;
+
+namespace net {
+class URLRequestContextGetter;
+}  // namespace net
+
+namespace syncer {
+
+// An implementation of AttachmentUploader.
+class SYNC_EXPORT AttachmentUploaderImpl : public AttachmentUploader,
+                                           public base::NonThreadSafe {
+ public:
+  // |url_prefix| is the URL prefix (including trailing slash) to be used when
+  // |uploading attachments.
+  AttachmentUploaderImpl(const std::string& url_prefix,
+                         const scoped_refptr<net::URLRequestContextGetter>&
+                             url_request_context_getter);
+  virtual ~AttachmentUploaderImpl();
+
+  // AttachmentUploader implementation.
+  virtual void UploadAttachment(const Attachment& attachment,
+                                const UploadCallback& callback) OVERRIDE;
+
+ private:
+  class UploadState;
+  typedef std::string UniqueId;
+  typedef base::ScopedPtrHashMap<UniqueId, UploadState> StateMap;
+
+  GURL GetUploadURLForAttachmentId(const AttachmentId& attachment_id) const;
+  void DeleteUploadStateFor(const UniqueId& unique_id);
+
+  std::string url_prefix_;
+  scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
+  StateMap state_map_;
+  DISALLOW_COPY_AND_ASSIGN(AttachmentUploaderImpl);
+};
+
+}  // namespace syncer
+
+#endif  // SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_UPLOADER_IMPL_H_