QUIC enable server push by default. Guarded by FLAGS_quic_enable_server_push_by_default.

net/quic/core/quic_spdy_session.cc

 // Copyright (c) 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.
 
 #include "net/quic/core/quic_spdy_session.h"
 
 #include <utility>
 
 #include "net/quic/core/quic_bug_tracker.h"
 #include "net/quic/core/quic_headers_stream.h"
 
 using base::StringPiece;
 using std::string;
 
 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
   // to null to avoid subsequent use of this session.
   for (auto* stream : *closed_streams()) {
     static_cast<QuicSpdyStream*>(stream)->ClearSession();
   }
   for (auto const& kv : dynamic_streams()) {
     static_cast<QuicSpdyStream*>(kv.second)->ClearSession();
   }
@@ skipping 125 matching lines @@
   const QuicVersion version = connection()->version();
   if (version > QUIC_VERSION_35 && config()->ForceHolBlocking(perspective())) {
     force_hol_blocking_ = true;
     // Autotuning makes sure that the headers stream flow control does
     // not get in the way, and normal stream and connection level flow
     // control are active anyway. This is really only for the client
     // side (and mainly there just in tests and toys), where
     // 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,
                                         const char* data,
                                         size_t len,
                                         bool fin) {
   QuicSpdyStream* stream = GetSpdyDataStream(stream_id);
   if (stream == nullptr) {
     return;
   }
   const QuicStreamOffset offset =
       stream->flow_controller()->highest_received_byte_offset();
   const QuicStreamFrame frame(stream_id, fin, offset, StringPiece(data, len));
   DVLOG(1) << "De-encapsulating DATA frame for stream " << stream_id
            << " offset " << offset << " len " << len << " fin " << fin;
   OnStreamFrame(frame);
 }
 
 }  // namespace net