Backed out changeset 762270e639cf (bug 1676078) for browser_datetime_datepicker.js failures CLOSED TREE

toolkit/content/tests/browser/browser_datetime_datepicker.js

@@ -266,8 +266,6 @@ add_task(async function test_datepicker_keyboard_open() {
     "waiting for open"
   );
 
-  let valueSet = helper.promisePickerValueSet();
-
   // NOTE: After the click, the first input field (the month one) is focused,
   // so down arrow will change the selected month.
   //
@@ -275,13 +273,14 @@ add_task(async function test_datepicker_keyboard_open() {
   // DATE_FORMAT and other bits around do the same).
   BrowserTestUtils.synthesizeKey("VK_DOWN", {}, browser);
 
-  await valueSet;
-
-  is(
-    helper.getElement(MONTH_YEAR).textContent,
-    DATE_FORMAT(new Date(prevMonth)),
-    "Should update date when updating months"
-  );
+  // It'd be good to use something else than waitForCondition for this but
+  // there's no exposed event atm when the value changes from the child.
+  await BrowserTestUtils.waitForCondition(() => {
+    return (
+      helper.getElement(MONTH_YEAR).textContent ==
+      DATE_FORMAT(new Date(prevMonth))
+    );
+  }, "Should update date when updating months");
 
   await helper.tearDown();
 });

toolkit/content/tests/browser/head.js

@@ -214,13 +214,6 @@ class DateTimeTestHelper {
     await readyPromise;
   }
 
-  promisePickerValueSet() {
-    return BrowserTestUtils.waitForEvent(
-      this.frame.contentDocument,
-      "PickerValueWasSet"
-    );
-  }
-
   /**
    * Find an element on the picker.
    *

toolkit/content/widgets/datepicker.js

@@ -315,7 +315,6 @@ function DatePicker(context) {
         day,
       });
       this._update({ noSmoothScroll: true });
-      document.dispatchEvent(new CustomEvent("PickerValueWasSet"));
     },
   };