Add a new method to QuicSpdySession

net/quic/quic_chromium_client_session.cc

Index: net/quic/quic_chromium_client_session.cc
diff --git a/net/quic/quic_chromium_client_session.cc b/net/quic/quic_chromium_client_session.cc
index b7ac6d1fff4d8e8c0810a01a7093c5fa3b18e493..1f46fe7d0388e30bcfcd452abe38d51ef7eee305 100644
--- a/net/quic/quic_chromium_client_session.cc
+++ b/net/quic/quic_chromium_client_session.cc
@@ -349,6 +349,13 @@ QuicChromiumClientSession::~QuicChromiumClientSession() {
       static_cast<base::HistogramBase::Sample>(stats.max_sequence_reordering));
 }
 
+void QuicChromiumClientSession::OnHeadersHeadOfLineBlocking(
+    QuicTime::Delta delta) {
+  UMA_HISTOGRAM_TIMES(
+      "Net.QuicSession.HeadersHOLBlockedTime",
+      base::TimeDelta::FromMicroseconds(delta.ToMicroseconds()));
+}
+
 void QuicChromiumClientSession::OnStreamFrame(const QuicStreamFrame& frame) {
   // Record total number of stream frames.
   UMA_HISTOGRAM_COUNTS("Net.QuicNumStreamFramesInPacket", 1);