SkTime: return timezone information

src/ports/SkTime_win.cpp

Index: src/ports/SkTime_win.cpp
diff --git a/src/ports/SkTime_win.cpp b/src/ports/SkTime_win.cpp
index bc0f8f008474bcfef45280d417863891cfc39eb8..19f4695a86bc498c76cb1d81d26e69e63ea70348 100644
--- a/src/ports/SkTime_win.cpp
+++ b/src/ports/SkTime_win.cpp
@@ -14,8 +14,22 @@ void SkTime::GetDateTime(DateTime* dt)
     if (dt)
     {
         SYSTEMTIME      st;
-        GetSystemTime(&st);
-
+        TIME_ZONE_INFORMATION timeZoneInfo;
+        int tz_bias;
+        GetLocalTime(&st);
+        // https://gist.github.com/wrl/8924636
+        switch (GetTimeZoneInformation(&timeZoneInfo)) {
+            case TIME_ZONE_ID_STANDARD:
+                tz_bias = -timeZoneInfo.Bias - timeZoneInfo.StandardBias;
+                break;
+            case TIME_ZONE_ID_DAYLIGHT:
+                tz_bias = -timeZoneInfo.Bias - timeZoneInfo.DaylightBias;
+                break;
+            default:
+                tz_bias = -timeZoneInfo.Bias;
+                break;
+        }
+        dt->fTimeZoneMinutes = SkToS16(tz_bias);
         dt->fYear       = st.wYear;
         dt->fMonth      = SkToU8(st.wMonth);
         dt->fDayOfWeek  = SkToU8(st.wDayOfWeek);