QUIC enable server push by default. Guarded by FLAGS_quic_enable_server_push_by_default.

net/quic/core/quic_spdy_session.cc

Index: net/quic/core/quic_spdy_session.cc
diff --git a/net/quic/core/quic_spdy_session.cc b/net/quic/core/quic_spdy_session.cc
index 65bfadeb7f9ec1f80314a3e8481903e368d19a3a..37a165cb0dc25a2697fca704455e70850f77eb85 100644
--- a/net/quic/core/quic_spdy_session.cc
+++ b/net/quic/core/quic_spdy_session.cc
@@ -16,7 +16,9 @@ namespace net {
 
 QuicSpdySession::QuicSpdySession(QuicConnection* connection,
                                  const QuicConfig& config)
-    : QuicSession(connection, config), force_hol_blocking_(false) {}
+    : QuicSession(connection, config),
+      force_hol_blocking_(false),
+      server_push_enabled_(false) {}
 
 QuicSpdySession::~QuicSpdySession() {
   // Set the streams' session pointers in closed and dynamic stream lists
@@ -162,6 +164,10 @@ void QuicSpdySession::OnConfigNegotiated() {
     // autotuning and/or large buffers are not enabled by default.
     headers_stream_->flow_controller()->set_auto_tune_receive_window(true);
   }
+
+  if (version > QUIC_VERSION_34) {
+    server_push_enabled_ = FLAGS_quic_enable_server_push_by_default;
+  }
 }
 
 void QuicSpdySession::OnStreamFrameData(QuicStreamId stream_id,