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 69%
rename from webkit/plugins/ppapi/time_conversion_unittest.cc
rename to ppapi/shared_impl/time_conversion_unittest.cc
index 84ad697f63db56d80f6f0e6b37354f505bdf3111..1ec70bf3e4a406ae6269f36faa6ee1fd7d866b9c 100644
--- a/webkit/plugins/ppapi/time_conversion_unittest.cc
+++ b/ppapi/shared_impl/time_conversion_unittest.cc
@@ -50,4 +50,24 @@ TEST(TimeConversion, EventTime) {
                 ppapi::EventTimeToPPTimeTicks(event_now));
 }
 
+TEST(TimeConversion, EpochTime) {
+  // Should be able to round-trip from epoch time.
+  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));
+
+  // Epoch time should be equal to a PP_Time of 0.0.
+  EXPECT_GE(kTimeSecondsSlop, fabs(ppapi::TimeToPPTime(epoch) - 0.0));
+  EXPECT_GE(kTimeInternalValueSlop,
+            abs(static_cast<int>(
+                (ppapi::PPTimeToTime(0.0) - epoch).ToInternalValue())));
+}
+
 }  // namespace ppapi