Implement HTTP/2 settings field trial parameters.

net/spdy/spdy_session.cc

Index: net/spdy/spdy_session.cc
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index 1fd628378b47822982837fac059febfcef8ad356..e5c00d351c8d74e9de0c662cdfed4ebbe6f7f545 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -655,7 +655,7 @@ SpdySession::SpdySession(const SpdySessionKey& spdy_session_key,
                          bool enable_sending_initial_data,
                          bool enable_ping_based_connection_checking,
                          size_t session_max_recv_window_size,
-                         size_t stream_max_recv_window_size,
+                         const SettingsMap& settings,
                          TimeFunc time_func,
                          ServerPushDelegate* push_delegate,
                          ProxyDelegate* proxy_delegate,
@@ -681,8 +681,10 @@ SpdySession::SpdySession(const SpdySessionKey& spdy_session_key,
       read_state_(READ_STATE_DO_READ),
       write_state_(WRITE_STATE_IDLE),
       error_on_close_(OK),
+      settings_(settings),
       max_concurrent_streams_(kInitialMaxConcurrentStreams),
-      max_concurrent_pushed_streams_(kMaxConcurrentPushedStreams),
+      max_concurrent_pushed_streams_(
+          settings.at(SETTINGS_MAX_CONCURRENT_STREAMS)),
       streams_initiated_count_(0),
       streams_pushed_count_(0),
       streams_pushed_and_claimed_count_(0),
@@ -697,7 +699,8 @@ SpdySession::SpdySession(const SpdySessionKey& spdy_session_key,
       session_recv_window_size_(0),
       session_unacked_recv_window_bytes_(0),
       stream_initial_send_window_size_(kDefaultInitialWindowSize),
-      stream_max_recv_window_size_(stream_max_recv_window_size),
+      max_header_table_size_(settings.at(SETTINGS_HEADER_TABLE_SIZE)),
+      stream_max_recv_window_size_(settings.at(SETTINGS_INITIAL_WINDOW_SIZE)),
       net_log_(
           NetLogWithSource::Make(net_log, NetLogSourceType::HTTP2_SESSION)),
       enable_sending_initial_data_(enable_sending_initial_data),
@@ -714,6 +717,11 @@ SpdySession::SpdySession(const SpdySessionKey& spdy_session_key,
       base::Bind(&NetLogSpdySessionCallback, &host_port_proxy_pair()));
   next_unclaimed_push_stream_sweep_time_ = time_func_() +
       base::TimeDelta::FromSeconds(kMinPushedStreamLifetimeSeconds);
+
+  DCHECK(settings_.find(SETTINGS_HEADER_TABLE_SIZE) != settings_.end());

[Ryan Hamilton, 2016/12/27 22:32:43]

Consider base::ContainsKey(settings_, SETTINGS_foo);

[Bence, 2016/12/28 00:53:24]

Done.

+  DCHECK(settings_.find(SETTINGS_MAX_CONCURRENT_STREAMS) != settings_.end());
+  DCHECK(settings_.find(SETTINGS_INITIAL_WINDOW_SIZE) != settings_.end());
+
   // TODO(mbelshe): consider randomization of the stream_hi_water_mark.
 }
 
@@ -755,7 +763,7 @@ void SpdySession::InitializeWithSocket(
   buffered_spdy_framer_.reset(new BufferedSpdyFramer());
   buffered_spdy_framer_->set_visitor(this);
   buffered_spdy_framer_->set_debug_visitor(this);
-  buffered_spdy_framer_->UpdateHeaderDecoderTableSize(kMaxHeaderTableSize);
+  buffered_spdy_framer_->UpdateHeaderDecoderTableSize(max_header_table_size_);
 
   net_log_.AddEvent(NetLogEventType::HTTP2_SESSION_INITIALIZED,
                     base::Bind(&NetLogSpdyInitializedCallback,
@@ -2646,12 +2654,35 @@ void SpdySession::SendInitialData() {
                       std::move(connection_header_prefix_frame));
 
   // First, notify the server about the settings they should use when
-  // communicating with us.
+  // communicating with us.  Only send settings that have a value different from
+  // the protocol default value.
   SettingsMap settings_map;
-  settings_map[SETTINGS_HEADER_TABLE_SIZE] = kMaxHeaderTableSize;
-  settings_map[SETTINGS_MAX_CONCURRENT_STREAMS] = kMaxConcurrentPushedStreams;
-  if (stream_max_recv_window_size_ != kDefaultInitialWindowSize) {
-    settings_map[SETTINGS_INITIAL_WINDOW_SIZE] = stream_max_recv_window_size_;
+  for (auto setting : settings_) {
+    switch (setting.first) {
+      case SETTINGS_HEADER_TABLE_SIZE:
+        if (setting.second == 4096)

[Ryan Hamilton, 2016/12/27 22:32:43]

Can we define these magic numbers somewhere?

[Bence, 2016/12/28 00:53:24]

Done.

+          continue;
+        break;
+      case SETTINGS_ENABLE_PUSH:
+        if (setting.second == 1)
+          continue;
+        break;
+      case SETTINGS_MAX_CONCURRENT_STREAMS:
+        break;
+      case SETTINGS_INITIAL_WINDOW_SIZE:
+        if (setting.second == 65535)
+          continue;
+        break;
+      case SETTINGS_MAX_FRAME_SIZE:
+        if (setting.second == 16384)
+          continue;
+        break;
+      case SETTINGS_MAX_HEADER_LIST_SIZE:
+        break;
+      default:
+        break;
+    }
+    settings_map.insert(setting);
   }
   SendSettings(settings_map);