QUIC - added force_hol_blocking field trial param to enable forced HOL blocking.

net/quic/test_tools/quic_test_packet_maker.cc

Index: net/quic/test_tools/quic_test_packet_maker.cc
diff --git a/net/quic/test_tools/quic_test_packet_maker.cc b/net/quic/test_tools/quic_test_packet_maker.cc
index 73d6fec01cce18567e89437291180865eefc54d7..4750ec3f93d8db01f9eb326196101eb5489e94bb 100644
--- a/net/quic/test_tools/quic_test_packet_maker.cc
+++ b/net/quic/test_tools/quic_test_packet_maker.cc
@@ -296,6 +296,7 @@ std::unique_ptr<QuicReceivedPacket> QuicTestPacketMaker::MakeDataPacket(
     base::StringPiece data) {
   InitializeHeader(packet_number, should_include_version);
   QuicStreamFrame frame(stream_id, fin, offset, data);
+  DVLOG(1) << "Adding frame: " << frame;
   return MakePacket(header_, QuicFrame(&frame));
 }
 
@@ -518,6 +519,24 @@ std::unique_ptr<QuicReceivedPacket> QuicTestPacketMaker::MakePushPromisePacket(
   }
 }
 
+std::unique_ptr<QuicReceivedPacket> QuicTestPacketMaker::MakeForceHolDataPacket(
+    QuicPacketNumber packet_number,
+    QuicStreamId stream_id,
+    bool should_include_version,
+    bool fin,
+    QuicStreamOffset* offset,
+    base::StringPiece data) {
+  SpdyDataIR spdy_data(stream_id, data);
+  spdy_data.set_fin(fin);
+  SpdySerializedFrame spdy_frame(
+      spdy_request_framer_.SerializeFrame(spdy_data));
+  InitializeHeader(packet_number, should_include_version);
+  QuicStreamFrame quic_frame(kHeadersStreamId, false, *offset,
+                             StringPiece(spdy_frame.data(), spdy_frame.size()));
+  *offset += spdy_frame.size();
+  return MakePacket(header_, QuicFrame(&quic_frame));
+}
+
 // If |offset| is provided, will use the value when creating the packet.
 // Will also update the value after packet creation.
 std::unique_ptr<QuicReceivedPacket>