Move timestamp_extrapolator.h to rtc_base/time/

This moves it from an API directory (system_wrappers/include/) to a
non-API directory, which is exactly what we want for utilities like
this.

BUG=webrtc:8445

Change-Id: I51dfe8879c28c91bd1c667fc47b4892373671e0f
Reviewed-on: https://webrtc-review.googlesource.com/21540
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22569}

modules/rtp_rtcp/BUILD.gn

@@ -210,6 +210,7 @@ rtc_static_library("rtp_rtcp") {
     "../../rtc_base:sequenced_task_checker",
     "../../rtc_base:stringutils",
     "../../rtc_base/system:fallthrough",
+    "../../rtc_base/time:timestamp_extrapolator",
     "../../system_wrappers",
     "../../system_wrappers:field_trial_api",
     "../../system_wrappers:metrics_api",

modules/rtp_rtcp/source/remote_ntp_time_estimator.cc

@@ -11,6 +11,7 @@
 #include "modules/rtp_rtcp/include/remote_ntp_time_estimator.h"
 
 #include "rtc_base/logging.h"
+#include "rtc_base/time/timestamp_extrapolator.h"
 #include "system_wrappers/include/clock.h"
 
 namespace webrtc {

modules/video_coding/BUILD.gn

@@ -153,6 +153,7 @@ rtc_static_library("video_coding") {
     "../../rtc_base:sequenced_task_checker",
     "../../rtc_base/experiments:alr_experiment",
     "../../rtc_base/system:fallthrough",
+    "../../rtc_base/time:timestamp_extrapolator",
     "../../system_wrappers",
     "../../system_wrappers:field_trial_api",
     "../../system_wrappers:metrics_api",

modules/video_coding/timing.cc

@@ -12,9 +12,9 @@
 
 #include <algorithm>
 
+#include "rtc_base/time/timestamp_extrapolator.h"
 #include "system_wrappers/include/clock.h"
 #include "system_wrappers/include/metrics.h"
-#include "system_wrappers/include/timestamp_extrapolator.h"
 
 namespace webrtc {
 

rtc_base/time/BUILD.gn

@@ -0,0 +1,24 @@
+# Copyright (c) 2018 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.
+
+import("../../webrtc.gni")
+if (is_android) {
+  import("//build/config/android/config.gni")
+  import("//build/config/android/rules.gni")
+}
+
+rtc_source_set("timestamp_extrapolator") {
+  sources = [
+    "timestamp_extrapolator.cc",
+    "timestamp_extrapolator.h",
+  ]
+  deps = [
+    "../..:typedefs",
+    "../../system_wrappers",
+  ]
+}

rtc_base/time/timestamp_extrapolator.cc

@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "system_wrappers/include/timestamp_extrapolator.h"
+#include "rtc_base/time/timestamp_extrapolator.h"
 
 #include <algorithm>
 
@@ -178,12 +178,14 @@ void TimestampExtrapolator::CheckForWrapArounds(uint32_t ts90khz) {
       // Forward wrap around
       _wrapArounds++;
     }
-  }
-  // This difference will probably be less than -2^31 if we have had a backward
-  // wrap around. Since it is casted to a Word32, it should be positive.
-  else if (static_cast<int32_t>(_prevWrapTimestamp - ts90khz) > 0) {
-    // Backward wrap around
-    _wrapArounds--;
+  } else {
+    // This difference will probably be less than -2^31 if we have had a
+    // backward wrap around. Since it is casted to a Word32, it should be
+    // positive.
+    if (static_cast<int32_t>(_prevWrapTimestamp - ts90khz) > 0) {
+      // Backward wrap around
+      _wrapArounds--;
+    }
   }
   _prevWrapTimestamp = ts90khz;
 }
@@ -193,9 +195,9 @@ bool TimestampExtrapolator::DelayChangeDetection(double error) {
   error = (error > 0) ? std::min(error, _accMaxError)
                       : std::max(error, -_accMaxError);
   _detectorAccumulatorPos =
-      std::max(_detectorAccumulatorPos + error - _accDrift, (double)0);
+      std::max(_detectorAccumulatorPos + error - _accDrift, double{0});
   _detectorAccumulatorNeg =
-      std::min(_detectorAccumulatorNeg + error + _accDrift, (double)0);
+      std::min(_detectorAccumulatorNeg + error + _accDrift, double{0});
   if (_detectorAccumulatorPos > _alarmThreshold ||
       _detectorAccumulatorNeg < -_alarmThreshold) {
     // Alarm

rtc_base/time/timestamp_extrapolator.h

@@ -8,8 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef SYSTEM_WRAPPERS_INCLUDE_TIMESTAMP_EXTRAPOLATOR_H_
-#define SYSTEM_WRAPPERS_INCLUDE_TIMESTAMP_EXTRAPOLATOR_H_
+#ifndef RTC_BASE_TIME_TIMESTAMP_EXTRAPOLATOR_H_
+#define RTC_BASE_TIME_TIMESTAMP_EXTRAPOLATOR_H_
 
 #include "system_wrappers/include/rw_lock_wrapper.h"
 #include "typedefs.h"  // NOLINT(build/include)
@@ -51,4 +51,4 @@ class TimestampExtrapolator {
 
 }  // namespace webrtc
 
-#endif  // SYSTEM_WRAPPERS_INCLUDE_TIMESTAMP_EXTRAPOLATOR_H_
+#endif  // RTC_BASE_TIME_TIMESTAMP_EXTRAPOLATOR_H_

system_wrappers/BUILD.gn

@@ -23,7 +23,6 @@ rtc_static_library("system_wrappers") {
     "include/rtp_to_ntp_estimator.h",
     "include/rw_lock_wrapper.h",
     "include/sleep.h",
-    "include/timestamp_extrapolator.h",
     "source/clock.cc",
     "source/cpu_features.cc",
     "source/cpu_info.cc",
@@ -40,7 +39,6 @@ rtc_static_library("system_wrappers") {
     "source/rw_lock_win.cc",
     "source/rw_lock_win.h",
     "source/sleep.cc",
-    "source/timestamp_extrapolator.cc",
   ]
 
   defines = []

video/BUILD.gn

@@ -94,6 +94,7 @@ rtc_static_library("video") {
     "../rtc_base:rtc_task_queue",
     "../rtc_base:sequenced_task_checker",
     "../rtc_base:weak_ptr",
+    "../rtc_base/time:timestamp_extrapolator",
     "../system_wrappers",
   ]
 

video/rtp_video_stream_receiver.cc

@@ -37,7 +37,6 @@
 #include "rtc_base/system/fallthrough.h"
 #include "system_wrappers/include/field_trial.h"
 #include "system_wrappers/include/metrics.h"
-#include "system_wrappers/include/timestamp_extrapolator.h"
 #include "video/receive_statistics_proxy.h"
 
 namespace webrtc {