Fix event warning crash when a listener is removed while dispatching event

third_party/WebKit/LayoutTests/inspector/input-event-warning.html

+<html>
+<head>
+<script src="../http/tests/inspector/inspector-test.js"></script>
+<script>
+
+function eventListenerSuicidal(event)
+{
+    event.target.removeEventListener("wheel", eventListenerSuicidal);
+}
+
+function eventListener1(e)
+{
+}
+
+function eventListener2(event)
+{
+    event.preventDefault();
+}
+
+function dispatchEvents()
+{
+    var target = document.createElement("div");
+    document.body.appendChild(target);
+    var touches = [new Touch({identifier: 1, clientX: 100, clientY: 100, target: target})];
+    var touchEventInit = {
+        cancelable: true,
+        touches: touches,
+        targetTouches: touches,
+        changedTouches: touches
+    };
+    var wheelEvent = new WheelEvent("wheel", { cancelable: true, deltaX: -120, deltaY: 120 });
+    var events = [
+        new WheelEvent("wheel", { cancelable: true, deltaX: -120, deltaY: 120 }),
+        new WheelEvent("wheel", { cancelable: false, deltaX: -120, deltaY: 120 }),
+        new MouseEvent("mousemove", { cancelable: true, clientX: 100, clinetY: 100, movementX: 0, movementY: 0 }),
+        new TouchEvent("touchstart", touchEventInit),
+        new TouchEvent("touchmove", touchEventInit),
+        new TouchEvent("touchend", touchEventInit),
+    ];
+
+    var eventTypes = ["wheel", "mousemove", "touchstart", "touchmove", "touchend"];
+    for (var type of eventTypes) {
+       target.addEventListener(type, eventListener1);
+       target.addEventListener(type, eventListener2);
+    }
+    var deadline = performance.now() + 100;
+    while (performance.now() < deadline) {};
+    if (window.testRunner)
+        window.testRunner.setDumpConsoleMessages(false);
+    for (var event of events)
+        target.dispatchEvent(event);
+
+    // Make sure we don't emit warnings twice, make another pass.
+    for (var event of events)
+        target.dispatchEvent(event);
+
+    // Make sure we don't crash.
+    target = document.createElement("div");
+    document.body.appendChild(target);
+    target.addEventListener("wheel", eventListenerSuicidal);
+    target.dispatchEvent(wheelEvent);
+}
+
+function test()
+{
+    WebInspector.multitargetConsoleModel.addEventListener(WebInspector.ConsoleModel.Events.MessageAdded, InspectorTest.safeWrap(onConsoleMessage));
+    step1();
+
+    function step1()
+    {
+        InspectorTest.mainTarget.pageAgent().setBlockedEventsWarningThreshold(30);
+        InspectorTest.evaluateInPage("dispatchEvents()", step2);
+    }
+
+    function step2()
+    {
+        InspectorTest.mainTarget.pageAgent().setBlockedEventsWarningThreshold(0.000001);
+        InspectorTest.addResult("There should be no warnings above this line");
+        InspectorTest.evaluateInPage("dispatchEvents()", () => InspectorTest.completeTest());
+    }
+
+    function onConsoleMessage(event)
+    {
+        var message = event.data;
+        var text = message.messageText;
+        InspectorTest.addResult(text.replace(/ \d+ ms/, " <number> ms"));
+    }
+}
+</script>
+</head>
+<body onload="runTest()">
+<p>Tests that console warnings are issued for a blocked event listener and that
+there is no crash when an offending listener is removed by the handler.</p>
+</div>
+</body>
+</html>