Add histogram stats for AV sync stream offset:

webrtc/system_wrappers/source/rtp_to_ntp_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 "testing/gtest/include/gtest/gtest.h"
 #include "webrtc/system_wrappers/include/rtp_to_ntp.h"
 
 namespace webrtc {
+namespace {
+const uint32_t kOneMsInNtpFrac = 4294967;
+const uint32_t kTimestampTicksPerMs = 90;
+}  // namespace
 
 TEST(WrapAroundTests, NoWrap) {
   EXPECT_EQ(0, CheckForWrapArounds(0xFFFFFFFF, 0xFFFFFFFE));
   EXPECT_EQ(0, CheckForWrapArounds(1, 0));
   EXPECT_EQ(0, CheckForWrapArounds(0x00010000, 0x0000FFFF));
 }
 
 TEST(WrapAroundTests, ForwardWrap) {
   EXPECT_EQ(1, CheckForWrapArounds(0, 0xFFFFFFFF));
   EXPECT_EQ(1, CheckForWrapArounds(0, 0xFFFF0000));
   EXPECT_EQ(1, CheckForWrapArounds(0x0000FFFF, 0xFFFFFFFF));
   EXPECT_EQ(1, CheckForWrapArounds(0x0000FFFF, 0xFFFF0000));
 }
 
 TEST(WrapAroundTests, BackwardWrap) {
   EXPECT_EQ(-1, CheckForWrapArounds(0xFFFFFFFF, 0));
   EXPECT_EQ(-1, CheckForWrapArounds(0xFFFF0000, 0));
   EXPECT_EQ(-1, CheckForWrapArounds(0xFFFFFFFF, 0x0000FFFF));
   EXPECT_EQ(-1, CheckForWrapArounds(0xFFFF0000, 0x0000FFFF));
 }
 
 TEST(WrapAroundTests, OldRtcpWrapped) {
   RtcpList rtcp;
   uint32_t ntp_sec = 0;
   uint32_t ntp_frac = 0;
   uint32_t timestamp = 0;
-  const uint32_t kOneMsInNtpFrac = 4294967;
-  const uint32_t kTimestampTicksPerMs = 90;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp -= kTimestampTicksPerMs;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp -= kTimestampTicksPerMs;
   int64_t timestamp_in_ms = -1;
   // This expected to fail since it's highly unlikely that the older RTCP
   // has a much smaller RTP timestamp than the newer.
   EXPECT_FALSE(RtpToNtpMs(timestamp, rtcp, &timestamp_in_ms));
 }
 
 TEST(WrapAroundTests, NewRtcpWrapped) {
   RtcpList rtcp;
   uint32_t ntp_sec = 0;
   uint32_t ntp_frac = 0;
   uint32_t timestamp = 0xFFFFFFFF;
-  const uint32_t kOneMsInNtpFrac = 4294967;
-  const uint32_t kTimestampTicksPerMs = 90;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp += kTimestampTicksPerMs;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   int64_t timestamp_in_ms = -1;
   EXPECT_TRUE(RtpToNtpMs(rtcp.back().rtp_timestamp, rtcp, &timestamp_in_ms));
   // Since this RTP packet has the same timestamp as the RTCP packet constructed
   // at time 0 it should be mapped to 0 as well.
   EXPECT_EQ(0, timestamp_in_ms);
 }
 
 TEST(WrapAroundTests, RtpWrapped) {
-  const uint32_t kOneMsInNtpFrac = 4294967;
-  const uint32_t kTimestampTicksPerMs = 90;
   RtcpList rtcp;
   uint32_t ntp_sec = 0;
   uint32_t ntp_frac = 0;
   uint32_t timestamp = 0xFFFFFFFF - 2 * kTimestampTicksPerMs;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp += kTimestampTicksPerMs;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp += kTimestampTicksPerMs;
   int64_t timestamp_in_ms = -1;
   EXPECT_TRUE(RtpToNtpMs(timestamp, rtcp, &timestamp_in_ms));
   // Since this RTP packet has the same timestamp as the RTCP packet constructed
   // at time 0 it should be mapped to 0 as well.
   EXPECT_EQ(2, timestamp_in_ms);
 }
 
 TEST(WrapAroundTests, OldRtp_RtcpsWrapped) {
-  const uint32_t kOneMsInNtpFrac = 4294967;
-  const uint32_t kTimestampTicksPerMs = 90;
   RtcpList rtcp;
   uint32_t ntp_sec = 0;
   uint32_t ntp_frac = 0;
   uint32_t timestamp = 0;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp += kTimestampTicksPerMs;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp -= 2*kTimestampTicksPerMs;
   int64_t timestamp_in_ms = -1;
   EXPECT_FALSE(RtpToNtpMs(timestamp, rtcp, &timestamp_in_ms));
 }
 
 TEST(WrapAroundTests, OldRtp_NewRtcpWrapped) {
-  const uint32_t kOneMsInNtpFrac = 4294967;
-  const uint32_t kTimestampTicksPerMs = 90;
   RtcpList rtcp;
   uint32_t ntp_sec = 0;
   uint32_t ntp_frac = 0;
   uint32_t timestamp = 0xFFFFFFFF;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp += kTimestampTicksPerMs;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp -= kTimestampTicksPerMs;
   int64_t timestamp_in_ms = -1;
   EXPECT_TRUE(RtpToNtpMs(timestamp, rtcp, &timestamp_in_ms));
   // Constructed at the same time as the first RTCP and should therefore be
   // mapped to zero.
   EXPECT_EQ(0, timestamp_in_ms);
 }
 
 TEST(WrapAroundTests, OldRtp_OldRtcpWrapped) {
-  const uint32_t kOneMsInNtpFrac = 4294967;
-  const uint32_t kTimestampTicksPerMs = 90;
   RtcpList rtcp;
   uint32_t ntp_sec = 0;
   uint32_t ntp_frac = 0;
   uint32_t timestamp = 0;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp -= kTimestampTicksPerMs;
   rtcp.push_front(RtcpMeasurement(ntp_sec, ntp_frac, timestamp));
   ntp_frac += kOneMsInNtpFrac;
   timestamp += 2*kTimestampTicksPerMs;
   int64_t timestamp_in_ms = -1;
   EXPECT_FALSE(RtpToNtpMs(timestamp, rtcp, &timestamp_in_ms));
 }
 };  // namespace webrtc