SkTime: return timezone information

tests/Time.cpp

Index: tests/Time.cpp
diff --git a/tests/Time.cpp b/tests/Time.cpp
index 0139654e1993ec51d711f86d1ff21ea43093c436..60dcd5527cdc5a2f30c8f55655c022323455c219 100644
--- a/tests/Time.cpp
+++ b/tests/Time.cpp
@@ -41,4 +41,16 @@ DEF_TEST(Time_GetDateTime, r) {
     REPORTER_ASSERT(r, dateTime.fMinute <= 59);
 
     REPORTER_ASSERT(r, dateTime.fSecond <= 60);  // leap seconds are 23:59:60
+
+    // The westernmost timezone is -12:00.
+    // The easternmost timezone is +14:00.
+    REPORTER_ASSERT(r, abs(SkToInt(dateTime.fTimeZoneMinutes)) <= 14 * 60);
+
+    SkString timeStamp;
+    dateTime.toISO8601(&timeStamp);
+    REPORTER_ASSERT(r, timeStamp.size() > 0);
+    if (r->verbose()) {  // `dm --veryVerbose`
+        SkDebugf("\nCurrent Time (ISO-8601 format): \"%s\"\n",
+                 timeStamp.c_str());
+    }
 }