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..b7be9326195e7c1a05389e08679070394a901edf
--- /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 */;

[apacible, 2015/12/11 23:54:59]

nit: indent to align with previous line

[miu, 2015/12/12 00:23:30]

Hahahah.  Irfan caught this too.  This is what `git cl format media` produced.

Okay, so I'm going to change this and continue the "hanging indentation" scheme
(by indenting 4 spaces to the right of the prior line).

BTW--There's a side discussion among the src/media owners about whether we
like/hate the indentation changes `git cl format` is making in the code.  The
guidance right now is to "do what you think is best."

+  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