Remove navigator.vibrate without user gesture.

third_party/WebKit/LayoutTests/resources/user-gesture-utils.js

+/**
+ * Simulates a user click on the element with an ID of [elementID] on optional
+ * [event] for features to be allowed in embedded iframes. Eg., for vibrate:
+ * https://www.chromestatus.com/feature/5644273861001216.
+ */
+function simulateUserClick(elementID, event) {

[mustaq, 2017/04/13 14:28:34]

The role of |event| parameter is unclear. Since this is unused for now, let's
remove it.

[binlu, 2017/04/13 15:11:11]

It's actually used in some test files, e.g.,
https://codereview.chromium.org/2778693004/diff/260001/third_party/WebKit/Lay...
https://codereview.chromium.org/2778693004/diff/260001/third_party/WebKit/Lay...

[mustaq, 2017/04/13 15:58:37]

I see, you have passed the missing frame coordinates now, thanks.

But since simulateUserClick() is a repeatedly used utility function, I would
like to simplify the interface to:
  simulateUserClick(x,y).
For the subframe case, the caller would use the frame coordinates appropriately.

[binlu, 2017/04/13 17:05:44]

Good point. Done.

+  if (window.eventSender) {
+    var element = document.getElementById(elementID);
+    if (event === undefined) {
+      eventSender.mouseMoveTo(element.offsetLeft + 2, element.offsetTop + 2);
+    } else {
+      eventSender.mouseMoveTo(element.offsetLeft + event.data.x + 2, element.offsetTop + event.data.x + 2);
+    }
+    eventSender.mouseDown();
+    eventSender.mouseUp();
+  }
+}
+