Adding the Copresence RpcHandler and HttpPost helper.

components/copresence/rpc/http_post.h

+// 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 COMPONENTS_COPRESENCE_RPC_HTTP_POST_H_
+#define COMPONENTS_COPRESENCE_RPC_HTTP_POST_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "net/url_request/url_fetcher_delegate.h"
+
+namespace google {
+namespace protobuf {
+class MessageLite;
+}
+}
+
+namespace net {
+class URLRequestContextGetter;
+}
+
+namespace copresence {
+
+/**
+ * This class handles all Apiary calls to the Copresence server.

[Daniel Erat, 2014/08/06 00:44:47]

use c++-style comments (//)

[Charlie, 2014/08/06 19:32:18]

Done. Is this in the style guide? I suppose Chromium doesn't use Doxygen?

+ * It configures the HTTP request appropriately and reports any errors.
+ * Clients should not attempt to delete this class, as it needs to
+ * persist until the HTTP request completes (or times out).
+ *
+ * TODO(ckehoe): Add retry logic.
+ * TODO(ckehoe): Template this class to parse the proto received.
+ */
+class HttpPost : public net::URLFetcherDelegate,
+                 public base::SupportsWeakPtr<HttpPost> {
+ public:
+  // Callback to receive the HTTP status code and body of the response (if any).
+  typedef base::Callback<void(int, const std::string&)> ResponseCallback;
+
+  // An id for testing url fetching.
+  static const int kUrlFetcherId = 1;
+
+  HttpPost(net::URLRequestContextGetter* url_context_getter,

[Daniel Erat, 2014/08/06 00:44:47]

document whether the ownership of this argument is transferred (if so, pass it
in a scoped_ptr instead)

[Charlie, 2014/08/06 19:32:18]

Done.

+           const std::string& rpc_name,
+           const scoped_ptr<google::protobuf::MessageLite> request_proto,

[Daniel Erat, 2014/08/06 00:44:47]

const reference instead of const scoped_ptr?

[Charlie, 2014/08/06 19:32:18]

Done.

+           const ResponseCallback& response_callback);
+
+ private:
+  // This class deletes itself when the request completes (or times out).
+  virtual ~HttpPost();
+
+  // Overridden from net::URLFetcherDelegate.
+  virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
+
+  ResponseCallback response_callback_;
+  scoped_ptr<net::URLFetcher> url_fetcher_;
+
+  DISALLOW_COPY_AND_ASSIGN(HttpPost);
+};
+
+}  // namespace copresence
+
+#endif  // COMPONENTS_COPRESENCE_RPC_HTTP_POST_H_