Non passive touch end or touch cancel listeners should not block scroll.

third_party/WebKit/LayoutTests/fast/events/touch/resources/compositor-touch-hit-rects.js

 function listener() {
 }
 
 function log(msg) {
     var span = document.createElement("span");
     document.getElementById("console").appendChild(span);
     span.innerHTML = msg + '<br />';
 }
 
 function nameForNode(node) {
@@ skipping 118 matching lines @@
     visualize = true;
 }
 
 if (window.internals) {
     window.internals.settings.setMockScrollbarsEnabled(true);
 }
 
 window.onload = function() {
     // Run each general test case.
     var tests = document.querySelectorAll('.testcase');
+
+    // Add document wide touchend and touchcancel events to ensure they
+    // are not added to the compositor hit test rects.

[tdresser, 2016/04/13 16:52:35]

Nit: we're adding listeners, not events.

I'm a bit confused by this comment. Why does adding these listeners effect
whether or not we add to the compositor hit test rects?

[dtapuska, 2016/04/13 18:00:15]

touchend and touchcancel use to be added to the hit test rects to block scroll.
So this is a negative test; in that I add the listeners and ensure the test
doesn't fail in adding the entire document to the hit test rects.

[tdresser, 2016/04/13 18:44:39]

Ah, makes sense.

Maybe reword "to ensure" to "and ensure".

[dtapuska, 2016/04/13 18:49:08]

Done.

+    document.documentElement.addEventListener('touchend', listener, false);
+    document.documentElement.addEventListener('touchcancel', listener, false);
+
     for ( var i = 0; i < tests.length; i++) {
         // Force a compositing update before testing each case to ensure that
         // any subsequent touch rect updates are actually done because of
         // the event handler changes in the test itself.
         if (window.internals)
             window.internals.forceCompositingUpdate(document);
         testElement(tests[i]);
     }
 
     if (window.additionalTests)
         additionalTests();
 
     if (!visualize && window.internals) {
         var testContainer = document.getElementById("tests");
         testContainer.parentNode.removeChild(testContainer);
     }
 
     document.documentElement.setAttribute('done', 'true');
 };