Add UMA to net::BidirectionalStream

net/http/bidirectional_stream.h

 // Copyright 2015 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 NET_HTTP_BIDIRECTIONAL_STREAM_H_
 #define NET_HTTP_BIDIRECTIONAL_STREAM_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
 #include "net/http/bidirectional_stream_impl.h"
 #include "net/http/http_stream_factory.h"
 #include "net/log/net_log.h"
 
 class GURL;
 
 namespace net {
 
 class HttpAuthController;
 class HttpNetworkSession;
@@ skipping 180 matching lines @@
                          SSLCertRequestInfo* cert_info) override;
   void OnHttpsProxyTunnelResponse(const HttpResponseInfo& response_info,
                                   const SSLConfig& used_ssl_config,
                                   const ProxyInfo& used_proxy_info,
                                   HttpStream* stream) override;
   void OnQuicBroken() override;
 
   // Helper method to notify delegate if there is an error.
   void NotifyFailed(int error);
 
+  void UpdateHistograms();
+
   // BidirectionalStreamRequestInfo used when requesting the stream.
   std::unique_ptr<BidirectionalStreamRequestInfo> request_info_;
   const BoundNetLog net_log_;
 
   HttpNetworkSession* session_;
 
   bool send_request_headers_automatically_;
   // Whether request headers have been sent, as indicated in OnStreamReady()
   // callback.
   bool request_headers_sent_;
@@ skipping 10 matching lines @@
   // non-NULL, if the |stream_request_| successfully finishes.
   std::unique_ptr<BidirectionalStreamImpl> stream_impl_;
 
   // Buffer used for reading.
   scoped_refptr<IOBuffer> read_buffer_;
   // List of buffers used for writing.
   std::vector<scoped_refptr<IOBuffer>> write_buffer_list_;
   // List of buffer length.
   std::vector<int> write_buffer_len_list_;
 
+  base::TimeTicks start_time_;

[mef, 2016/08/11 15:42:19]

Would it make sense to replace individual timeticks with net::LoadTimingInfo
here? Some of the fields will be unused, but it could make it easier to use for
Metrics API implementation.

[xunjieli, 2016/08/11 19:37:09]

That's a great idea! How about doing this as a follow-up? I'd like to add
support for LoadTimingInfo in QUIC as well. I can refactor this once that is
ready. What do you think?

LoadTimingInfo doesn't have a counter part for |read_end_time_|, so that's
something we need to investigate as well for the metrics API.

[mef, 2016/08/12 15:44:45]

sgtm. Interesting observation about missing read_end_time_, I didn't realize
that. 

+  base::TimeTicks read_start_time_;
+  base::TimeTicks read_end_time_;
+  base::TimeTicks send_start_time_;
+  base::TimeTicks send_end_time_;
+
   base::WeakPtrFactory<BidirectionalStream> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BidirectionalStream);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_BIDIRECTIONAL_STREAM_H_