Fix PPAPI time conversion code to handle epoch times.

ppapi/shared_impl/time_conversion_unittest.cc

Index: ppapi/shared_impl/time_conversion_unittest.cc
diff --git a/webkit/plugins/ppapi/time_conversion_unittest.cc b/ppapi/shared_impl/time_conversion_unittest.cc
similarity index 76%
rename from webkit/plugins/ppapi/time_conversion_unittest.cc
rename to ppapi/shared_impl/time_conversion_unittest.cc
index 84ad697f63db56d80f6f0e6b37354f505bdf3111..b8af346d8f62c3e1db9e28aee3fea51101eee5ed 100644
--- a/webkit/plugins/ppapi/time_conversion_unittest.cc
+++ b/ppapi/shared_impl/time_conversion_unittest.cc
@@ -50,4 +50,18 @@ TEST(TimeConversion, EventTime) {
                 ppapi::EventTimeToPPTimeTicks(event_now));
 }
 
+TEST(TimeConversion, EpochTime) {
+  // Should be able to round-trip.
+  base::Time epoch = base::Time::UnixEpoch();
+  base::Time converted = ppapi::PPTimeToTime(TimeToPPTime(epoch));
+  EXPECT_GE(kTimeInternalValueSlop,
+            abs(static_cast<int>((converted - epoch).ToInternalValue())));
+
+  // Units should be in seconds.
+  base::Time one_second_from_epoch = epoch + base::TimeDelta::FromSeconds(1);
+  double converted_one_second_from_epoch =
+      ppapi::TimeToPPTime(one_second_from_epoch) - ppapi::TimeToPPTime(epoch);
+  EXPECT_GE(kTimeSecondsSlop, fabs(converted_one_second_from_epoch - 1));

[Scott Hess - ex-Googler, 2012/12/13 18:35:24]

I think you should have a straight up test that PPTimeToTime(0.0) returns
UnixEpoch(), or relate an offset from the epoch in seconds between PPTime and
Time, something like:
  EXPECT_EQ(PPTimeToTime(0.0) + FromSeconds(1), PPTimeToTime(1.0));

[raymes, 2012/12/14 17:28:22]

Done.

+}
+
 }  // namespace ppapi