Update to current webrtc library

This is from the upstream library commit id
3326535126e435f1ba647885ce43a8f0f3d317eb, corresponding to Chromium
88.0.4290.1.

webrtc/rtc_base/time_utils.h

@@ -0,0 +1,139 @@
+/*
+ *  Copyright 2005 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.
+ */
+
+#ifndef RTC_BASE_TIME_UTILS_H_
+#define RTC_BASE_TIME_UTILS_H_
+
+#include <stdint.h>
+#include <time.h>
+
+#include "rtc_base/checks.h"
+#include "rtc_base/system/rtc_export.h"
+
+namespace rtc {
+
+static const int64_t kNumMillisecsPerSec = INT64_C(1000);
+static const int64_t kNumMicrosecsPerSec = INT64_C(1000000);
+static const int64_t kNumNanosecsPerSec = INT64_C(1000000000);
+
+static const int64_t kNumMicrosecsPerMillisec =
+    kNumMicrosecsPerSec / kNumMillisecsPerSec;
+static const int64_t kNumNanosecsPerMillisec =
+    kNumNanosecsPerSec / kNumMillisecsPerSec;
+static const int64_t kNumNanosecsPerMicrosec =
+    kNumNanosecsPerSec / kNumMicrosecsPerSec;
+
+// TODO(honghaiz): Define a type for the time value specifically.
+
+class ClockInterface {
+ public:
+  virtual ~ClockInterface() {}
+  virtual int64_t TimeNanos() const = 0;
+};
+
+// Sets the global source of time. This is useful mainly for unit tests.
+//
+// Returns the previously set ClockInterface, or nullptr if none is set.
+//
+// Does not transfer ownership of the clock. SetClockForTesting(nullptr)
+// should be called before the ClockInterface is deleted.
+//
+// This method is not thread-safe; it should only be used when no other thread
+// is running (for example, at the start/end of a unit test, or start/end of
+// main()).
+//
+// TODO(deadbeef): Instead of having functions that access this global
+// ClockInterface, we may want to pass the ClockInterface into everything
+// that uses it, eliminating the need for a global variable and this function.
+RTC_EXPORT ClockInterface* SetClockForTesting(ClockInterface* clock);
+
+// Returns previously set clock, or nullptr if no custom clock is being used.
+RTC_EXPORT ClockInterface* GetClockForTesting();
+
+#if defined(WINUWP)
+// Synchronizes the current clock based upon an NTP server's epoch in
+// milliseconds.
+void SyncWithNtp(int64_t time_from_ntp_server_ms);
+#endif  // defined(WINUWP)
+
+// Returns the actual system time, even if a clock is set for testing.
+// Useful for timeouts while using a test clock, or for logging.
+int64_t SystemTimeNanos();
+int64_t SystemTimeMillis();
+
+// Returns the current time in milliseconds in 32 bits.
+uint32_t Time32();
+
+// Returns the current time in milliseconds in 64 bits.
+RTC_EXPORT int64_t TimeMillis();
+// Deprecated. Do not use this in any new code.
+inline int64_t Time() {
+  return TimeMillis();
+}
+
+// Returns the current time in microseconds.
+RTC_EXPORT int64_t TimeMicros();
+
+// Returns the current time in nanoseconds.
+RTC_EXPORT int64_t TimeNanos();
+
+// Returns a future timestamp, 'elapsed' milliseconds from now.
+int64_t TimeAfter(int64_t elapsed);
+
+// Number of milliseconds that would elapse between 'earlier' and 'later'
+// timestamps.  The value is negative if 'later' occurs before 'earlier'.
+int64_t TimeDiff(int64_t later, int64_t earlier);
+int32_t TimeDiff32(uint32_t later, uint32_t earlier);
+
+// The number of milliseconds that have elapsed since 'earlier'.
+inline int64_t TimeSince(int64_t earlier) {
+  return TimeMillis() - earlier;
+}
+
+// The number of milliseconds that will elapse between now and 'later'.
+inline int64_t TimeUntil(int64_t later) {
+  return later - TimeMillis();
+}
+
+class TimestampWrapAroundHandler {
+ public:
+  TimestampWrapAroundHandler();
+
+  int64_t Unwrap(uint32_t ts);
+
+ private:
+  uint32_t last_ts_;
+  int64_t num_wrap_;
+};
+
+// Convert from tm, which is relative to 1900-01-01 00:00 to number of
+// seconds from 1970-01-01 00:00 ("epoch"). Don't return time_t since that
+// is still 32 bits on many systems.
+int64_t TmToSeconds(const tm& tm);
+
+// Return the number of microseconds since January 1, 1970, UTC.
+// Useful mainly when producing logs to be correlated with other
+// devices, and when the devices in question all have properly
+// synchronized clocks.
+//
+// Note that this function obeys the system's idea about what the time
+// is. It is not guaranteed to be monotonic; it will jump in case the
+// system time is changed, e.g., by some other process calling
+// settimeofday. Always use rtc::TimeMicros(), not this function, for
+// measuring time intervals and timeouts.
+int64_t TimeUTCMicros();
+
+// Return the number of milliseconds since January 1, 1970, UTC.
+// See above.
+int64_t TimeUTCMillis();
+
+}  // namespace rtc
+
+#endif  // RTC_BASE_TIME_UTILS_H_