Add traffic annotation to SpdySession::TryCreatePushStream.

Local annotation is added to SpdySession::TryCreatePushStream.

Bug: 656607
Change-Id: I164d9d6df34b9f38e6077c5746a04f2e53a7061d
Reviewed-on: https://chromium-review.googlesource.com/951728
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Reviewed-by: Ryan Hamilton <rch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541747}

net/spdy/chromium/spdy_session.cc

@@ -1739,11 +1739,32 @@ void SpdySession::TryCreatePushStream(SpdyStreamId stream_id,
                  stream_id),
       base::TimeDelta::FromSeconds(kPushedStreamLifetimeSeconds));
 
-  // TODO(https://crbug.com/656607): Add proper annotation here.
+  net::NetworkTrafficAnnotationTag traffic_annotation =
+      net::DefineNetworkTrafficAnnotation("spdy_push_stream", R"(
+        semantics {
+          sender: "Spdy Session"
+          description:
+            "When a web server needs to push a response to a client, an "
+            "incoming stream is created to reply the client with pushed "
+            "message instead of a message from the network."
+          trigger:
+            "A request by a server to push a response to the client."
+          data: "None."
+          destination: OTHER
+          destination_other:
+            "This stream is not used for sending data."
+        }
+        policy {
+          cookies_allowed: NO
+          setting: "This feature cannot be disabled."
+          policy_exception_justification: "Essential for navigation."
+        }
+    )");
+
   auto stream = std::make_unique<SpdyStream>(
       SPDY_PUSH_STREAM, GetWeakPtr(), gurl, request_priority,
       stream_initial_send_window_size_, stream_max_recv_window_size_, net_log_,
-      NO_TRAFFIC_ANNOTATION_BUG_656607);
+      traffic_annotation);
   stream->set_stream_id(stream_id);
 
   // Convert RequestPriority to a SpdyPriority to send in a PRIORITY frame.

tools/traffic_annotation/summary/annotations.xml

@@ -210,6 +210,7 @@ Refer to README.md for content description and update process.
  <item id="sigined_exchange_cert_fetcher" hash_code="79442849" type="0" content_hash_code="8138156" os_list="linux,windows" file_path="content/browser/web_package/signed_exchange_cert_fetcher.cc"/>
  <item id="signed_in_profile_avatar" hash_code="108903331" type="0" content_hash_code="72850619" os_list="linux,windows" file_path="chrome/browser/profiles/profile_downloader.cc"/>
  <item id="socket_bio_adapter" hash_code="516551" type="0" content_hash_code="21643352" os_list="linux,windows" file_path="net/socket/socket_bio_adapter.cc"/>
+ <item id="spdy_push_stream" hash_code="36915753" type="0" content_hash_code="69224629" os_list="linux,windows" file_path="net/spdy/chromium/spdy_session.cc"/>
  <item id="spdy_session_control" hash_code="57143548" type="0" content_hash_code="29815792" os_list="linux,windows" file_path="net/spdy/chromium/spdy_session.cc"/>
  <item id="speech_recognition_downstream" hash_code="26096088" type="0" content_hash_code="120733233" os_list="linux,windows" file_path="content/browser/speech/speech_recognition_engine.cc"/>
  <item id="speech_recognition_upstream" hash_code="66846958" type="0" content_hash_code="7706219" os_list="linux,windows" file_path="content/browser/speech/speech_recognition_engine.cc"/>