Add a minimal AttachmentUploaderImpl.

sync/internal_api/attachments/attachment_server_url_builder.cc

Index: sync/internal_api/attachments/attachment_server_url_builder.cc
diff --git a/sync/internal_api/attachments/attachment_server_url_builder.cc b/sync/internal_api/attachments/attachment_server_url_builder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3f871dd4dc63d007ad4ed42aa38cbafec2b35eaa
--- /dev/null
+++ b/sync/internal_api/attachments/attachment_server_url_builder.cc
@@ -0,0 +1,47 @@
+// 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/attachment_server_url_builder.h"
+
+#include "base/logging.h"
+#include "base/strings/stringprintf.h"
+#include "sync/protocol/sync.pb.h"
+
+namespace {
+
+const char kPath[] = "uploads/";
+
+}  // namespace
+
+namespace syncer {
+
+AttachmentServerURLBuilder::AttachmentServerURLBuilder(const Scheme& scheme,
+                                                       const std::string& host,
+                                                       const int port) {
+  std::string scheme_string;
+  switch (scheme) {
+    case SCHEME_HTTPS:
+      scheme_string = "https";
+      break;
+    case SCHEME_HTTP:
+      scheme_string = "http";
+      break;
+    default:
+      NOTREACHED();
+  };
+  url_prefix_ = base::StringPrintf(
+      "%s://%s:%d/%s", scheme_string.c_str(), host.c_str(), port, kPath);
+}
+
+AttachmentServerURLBuilder::~AttachmentServerURLBuilder() {
+}
+
+GURL AttachmentServerURLBuilder::BuildUploadURLFor(
+    const AttachmentId& attachment_id) const {
+  std::string unique_id = attachment_id.GetProto().unique_id();
+  DCHECK(!unique_id.empty());
+  return GURL(url_prefix_ + unique_id);

[pavely, 2014/05/14 18:38:31]

Currently unique_id is guid, but it wasn't the case and it might change in the
future. Let's URLEncode it.

[maniscalco, 2014/05/14 21:59:03]

Of course, we'd then need to decode it on the server side.  What do you think
about restricting unique_id to be "url safe" instead?  Seems like that would be
simpler.  Also, we can rely on the GUID format to never change and be "url
safe".

+}
+
+}  // namespace syncer