Bug 1222866: P2. Add gtest checking on seconds -> microseconds -> seconds. r=gerald

dom/media/gtest/TestTimeUnit.cpp

@@ -0,0 +1,22 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+#include "TimeUnits.h"
+#include <algorithm>
+#include <vector>
+
+using namespace mozilla;
+
+TEST(TimeUnit, Rounding)
+{
+  int64_t usecs = 66261715;
+  double seconds = media::TimeUnit::FromMicroseconds(usecs).ToSeconds();
+  EXPECT_EQ(media::TimeUnit::FromSeconds(seconds).ToMicroseconds(), usecs);
+
+  seconds = 4.169470;
+  usecs = 4169470;
+  EXPECT_EQ(media::TimeUnit::FromSeconds(seconds).ToMicroseconds(), usecs);
+}