Improve testSetTimezone and check local hour

Bug: 1144403
Change-Id: Ib3a78b49d328120bf51c332f61f57299933e8088
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2545867
Commit-Queue: Shengfa Lin <shengfa@google.com>
Reviewed-by: John Chen <johnchen@chromium.org>
Reviewed-by: Shengfa Lin <shengfa@google.com>
Cr-Commit-Position: refs/heads/master@{#828786}

chrome/test/chromedriver/test/run_py_tests.py

@@ -2703,15 +2703,30 @@ class ChromeDriverTest(ChromeDriverBaseTestWithWebServer):
     self.assertEquals('test report message', report['body']['message']);
 
   def testSetTimezone(self):
+    defaultTimeZoneScript = '''
+       return (new Intl.DateTimeFormat()).resolvedOptions().timeZone;
+       ''';
+    localHourScript = '''
+       return (new Date("2020-10-10T00:00:00Z")).getHours();
+       ''';
+
     self._driver.Load(self.GetHttpUrlForFile('/chromedriver/empty.html'))
+
+    # Test to switch to Taipei
     self._driver.SetTimezone('Asia/Taipei');
-    timeZone = self._driver.ExecuteScript(
-        'return (new Intl.DateTimeFormat()).resolvedOptions().timeZone;')
+    timeZone = self._driver.ExecuteScript(defaultTimeZoneScript)
     self.assertEquals('Asia/Taipei', timeZone);
-    self._driver.SetTimezone('Asia/Hong_Kong');
-    timeZone = self._driver.ExecuteScript(
-        'return (new Intl.DateTimeFormat()).resolvedOptions().timeZone;')
-    self.assertEquals('Asia/Hong_Kong', timeZone);
+    localHour = self._driver.ExecuteScript(localHourScript)
+    # Taipei time is GMT+8. Not observes DST.
+    self.assertEquals(8, localHour);
+
+    # Test to switch to Tokyo
+    self._driver.SetTimezone('Asia/Tokyo');
+    timeZone = self._driver.ExecuteScript(defaultTimeZoneScript)
+    self.assertEquals('Asia/Tokyo', timeZone);
+    localHour = self._driver.ExecuteScript(localHourScript)
+    # Tokyo time is GMT+9. Not observes DST.
+    self.assertEquals(9, localHour);
 
   def GetPermissionWithQuery(self, query):
     script = """