Replace uses of raw uint32's with a type-checked RtpTimeTicks data type.

media/cast/common/rtp_time.cc

Index: media/cast/common/rtp_time.cc
diff --git a/media/cast/common/rtp_time.cc b/media/cast/common/rtp_time.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1fb1b9b71c640f864ef81064b1433b4fe0bfb4d9
--- /dev/null
+++ b/media/cast/common/rtp_time.cc
@@ -0,0 +1,74 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/cast/common/rtp_time.h"
+
+#include <limits>
+#include <sstream>
+
+namespace media {
+namespace cast {
+
+namespace {
+
+// Returns the base::TimeDelta nearest to the time represented by a tick count
+// in the given timebase.
+base::TimeDelta TicksToTimeDelta(int64_t ticks, int timebase) {
+  DCHECK_GT(timebase, 0);
+  const double micros = static_cast<double>(ticks) / timebase *
+                            base::Time::kMicrosecondsPerSecond +
+                                0.5 /* rounding */;
+  DCHECK_LT(micros, static_cast<double>(std::numeric_limits<int64_t>::max()));
+  return base::TimeDelta::FromMicroseconds(static_cast<int64_t>(micros));
+}
+
+// Returns the tick count in the given timebase nearest to the base::TimeDelta.
+int64_t TimeDeltaToTicks(base::TimeDelta delta, int timebase) {
+  DCHECK_GT(timebase, 0);
+  const double ticks = delta.InSecondsF() * timebase + 0.5 /* rounding */;
+  DCHECK_LT(ticks, static_cast<double>(std::numeric_limits<int64_t>::max()));
+  return static_cast<int64_t>(ticks);
+}
+
+}  // namespace
+
+std::ostream& operator<<(std::ostream& out, const RtpTimeDelta rhs) {
+  if (rhs.value_ >= 0)
+    out << "RTP+";
+  else
+    out << "RTP";
+  return out << rhs.value_;
+}
+
+std::ostream& operator<<(std::ostream& out, const RtpTimeTicks rhs) {
+  return out << "RTP@" << rhs.value_;
+}
+
+base::TimeDelta RtpTimeDelta::ToTimeDelta(int rtp_timebase) const {
+  return TicksToTimeDelta(value_, rtp_timebase);
+}
+
+// static
+RtpTimeDelta RtpTimeDelta::FromTimeDelta(base::TimeDelta delta,
+                                         int rtp_timebase) {
+  return RtpTimeDelta(TimeDeltaToTicks(delta, rtp_timebase));
+}
+
+// static
+RtpTimeDelta RtpTimeDelta::FromTicks(int64_t ticks) {
+  return RtpTimeDelta(ticks);
+}
+
+base::TimeDelta RtpTimeTicks::ToTimeDelta(int rtp_timebase) const {
+  return TicksToTimeDelta(value_, rtp_timebase);
+}
+
+// static
+RtpTimeTicks RtpTimeTicks::FromTimeDelta(base::TimeDelta delta,
+                                         int rtp_timebase) {
+  return RtpTimeTicks(TimeDeltaToTicks(delta, rtp_timebase));
+}
+
+}  // namespace cast
+}  // namespace media