Revert "Handle empty timezone on in-session set date time dialog"

This reverts commit 4ccdb965.

Reason for revert: https://crbug.com/990203 (introduces a flaky test that fails at certain times of day)

Original change's description:
> Handle empty timezone on in-session set date time dialog
> 
> Bug: 988107
> Change-Id: Ia9c12a9342342bc080f73ddbe5ba86531b29997e
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1724696
> Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
> Reviewed-by: Aga Wronska <agawronska@chromium.org>
> Commit-Queue: Henrique Grandinetti <hgrandinetti@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#683159}

TBR=michaelpg@chromium.org,agawronska@chromium.org,hgrandinetti@chromium.org

Change-Id: I73c1230760be4eda32238fe9cacf8255fa56f15e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 988107, 990203
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1732074Reviewed-by: Matt Giuca <mgiuca@chromium.org>
Commit-Queue: Matt Giuca <mgiuca@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683444}

chrome/browser/resources/chromeos/set_time_dialog/set_time_dialog.js

@@ -267,15 +267,11 @@ Polymer({
   applyTime_: function() {
     const now = this.getInputTime_();
 
-    if (this.isTimezoneVisible_) {
-      // Add timezone offset to get real time. This is only necessary when the
-      // timezone was updated, which is only possible when the dropdown is
-      // visible.
-      const timezoneDelta = getTimezoneDelta(
-          /** @type {string} */ (loadTimeData.getValue('currentTimezoneId')),
-          this.selectedTimezone_);
-      now.setMilliseconds(now.getMilliseconds() + timezoneDelta);
-    }
+    // Add timezone offset to get real time.
+    const timezoneDelta = getTimezoneDelta(
+        /** @type {string} */ (loadTimeData.getValue('currentTimezoneId')),
+        this.selectedTimezone_);
+    now.setMilliseconds(now.getMilliseconds() + timezoneDelta);
 
     const seconds = Math.floor(now / 1000);
     this.browserProxy_.setTimeInSeconds(seconds);

chrome/test/data/webui/set_time_dialog_browsertest.js

@@ -187,38 +187,6 @@ TEST_F('SetTimeDialogBrowserTest', 'All', function() {
             assertGT(timeInSeconds, todaySeconds);
           });
     });
-
-    suite('NullTimezone', () => {
-      suiteSetup(() => {
-        loadTimeData.overrideValues({
-          currentTimezoneId: '',
-          timezoneList: [],
-        });
-      });
-
-      test('SetDateNullTimezone', () => {
-        const dateInput = setTimeElement.$$('#dateInput');
-        assertTrue(!!dateInput);
-
-        assertEquals(null, setTimeElement.$$('#timezoneSelect'));
-
-        // Simulate the user changing the date picker backward by one hour.
-        const today = dateInput.valueAsDate;
-        const nextWeek = new Date(today.getTime() - 60 * 60 * 1000);
-        dateInput.focus();
-        dateInput.valueAsDate = nextWeek;
-        setTimeElement.$$('#doneButton').click();
-
-        // Verify the page sends a request to move time backward.
-        return testBrowserProxy.whenCalled('setTimeInSeconds')
-            .then(timeInSeconds => {
-              const todaySeconds = today.getTime() / 1000;
-              // The exact value isn't important (it depends on the current
-              // time).
-              assertGT(todaySeconds, timeInSeconds);
-            });
-      });
-    });
   });
 
   mocha.run();