Add a flag to update hover effect when a layout is changed

third_party/WebKit/LayoutTests/fast/events/resources/expect-cursor-update.js

 // Wait until any mouse cursor update has completed, then verify the cursor info
 // is what's expected and call the provided continuation.
 // We need to poll to ensure EventHandler's cursor update timer has had a chance to fire.
 function expectCursorUpdate(expectedInfo, completion) {
     // Need to give style application a chance to take effect first.
     requestAnimationFrame(function() {
         // Note that cursorUpdatePending should (almost?) always be true at this
         // point, but we probably shouldn't depend on that in case scheduler changes
         // result in rAF not firing until after the cursor update timer as already
         // fired.
         var onFrame = function() {
             if (internals.cursorUpdatePending) {
                 requestAnimationFrame(onFrame);
             } else {
                 shouldBeEqualToString('internals.getCurrentCursorInfo()', expectedInfo);
                 completion();
             }
         }
         requestAnimationFrame(onFrame);
     });
 }
+
+function expectSendFakeMouseMove(expectedInfo, completion) {
+    // Need to give style application a chance to take effect first.
+    requestAnimationFrame(function() {
+        // Note that fakeMouseMovePending should (almost?) always be true at this
+        // point, but we probably shouldn't depend on that in case scheduler changes
+        // result in rAF not firing until after the fake_mouse_move_event_timer_ as
+        // already fired.
+        var onFrame = function() {
+            if (internals.fakeMouseMovePending) {

[Navid Zolghadr, 2017/07/05 17:37:33]

Is there any reason we don't wait for cursorUpdatePending as well? Does
fakeMouseMovePending cover that?

[lanwei, 2017/07/06 03:04:34]

Yes, they are different. When we sent fake mouse move events, and we have to use
fakeMouseMovePending to decide if we have received the events. Using
cursorUpdatePending will give the wrong result.

+                requestAnimationFrame(onFrame);
+            } else {
+                shouldBeEqualToString('internals.getCurrentCursorInfo()', expectedInfo);
+                completion();
+            }
+        }
+        requestAnimationFrame(onFrame);
+    });
+}