Delete stl_util.h. Unused since cl https://codereview.webrtc.org/2447103002

webrtc/modules/rtp_rtcp/source/rtp_sender_unittest.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include <memory>
 #include <vector>
 
 #include "webrtc/base/buffer.h"
 #include "webrtc/base/rate_limiter.h"
 #include "webrtc/logging/rtc_event_log/mock/mock_rtc_event_log.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_cvo.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_header_parser.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_format_video_generic.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_header_extension.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_packet_received.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_packet_to_send.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_sender.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_sender_video.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
-#include "webrtc/system_wrappers/include/stl_util.h"
 #include "webrtc/test/field_trial.h"
 #include "webrtc/test/gmock.h"
 #include "webrtc/test/gtest.h"
 #include "webrtc/test/mock_transport.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 namespace {
 const int kTransmissionTimeOffsetExtensionId = 1;
@@ skipping 1413 matching lines @@
                         PacketInfo::kNotAProbe))
       .Times(1);
   EXPECT_CALL(mock_overhead_observer,
               OnOverheadChanged(kTransportOverheadBytesPerPacket +
                                 kRtpOverheadBytesPerPacket))
       .Times(1);
   SendGenericPayload();
 }
 
 }  // namespace webrtc