Support registering and dispatching passive event listeners.

third_party/WebKit/LayoutTests/fast/events/eventlisteneroptions/passive_query.html

Index: third_party/WebKit/LayoutTests/fast/events/eventlisteneroptions/passive_query.html
diff --git a/third_party/WebKit/LayoutTests/fast/events/eventlisteneroptions/capture_query.html b/third_party/WebKit/LayoutTests/fast/events/eventlisteneroptions/passive_query.html
similarity index 69%
copy from third_party/WebKit/LayoutTests/fast/events/eventlisteneroptions/capture_query.html
copy to third_party/WebKit/LayoutTests/fast/events/eventlisteneroptions/passive_query.html
index e7c9e5ef2e7000be130b447adbd2b373a136bef6..dfd2394ad18fedb1576a9d644aad4948004e0fce 100644
--- a/third_party/WebKit/LayoutTests/fast/events/eventlisteneroptions/capture_query.html
+++ b/third_party/WebKit/LayoutTests/fast/events/eventlisteneroptions/passive_query.html
@@ -5,11 +5,11 @@
 
 <script>
 test(function(t) {
-    var supportsCapture = false;
+    var supportsPassive = false;
     var query_function = function(e) {};
     var query_options = {
-        get capture() {
-            supportsCapture = true;
+        get passive() {
+            supportsPassive = true;
             return false;
         },
         get dummy() {
@@ -19,10 +19,10 @@ test(function(t) {
     };
 
     document.addEventListener('test_event', query_function, query_options);
-    assert_equals(supportsCapture, internals.runtimeFlags.eventListenerOptionsEnabled);
-    supportsCapture = false;
+    assert_equals(supportsPassive, internals.runtimeFlags.eventListenerOptionsEnabled);

[Rick Byers, 2016/01/08 19:32:56]

I guess this could be a good place to verify that the runtime enabled feature is
correctly supporting the feature detection.  I.e. instead of just testing
whatever the default state is, assert that it's enabled (I don't think we'd ever
put the feature below "test" status), verify the feature detection passes, then
disable it and verify the feature detection fails.  WDYT?

[dtapuska, 2016/01/11 18:56:28]

Is this not doing it when it runs via the stable test?

[Rick Byers, 2016/01/11 22:37:05]

Ah, I forgot this entire directly is enabled for virtual/stable
(https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...).

The more common pattern I think is to explicitly toggle the
RuntimeEnabledFeature state, but this is fine too.

Maybe add a comment here (and in the other test) just mentioning that this tests
expects to be run with and without the feature enabled via virtual/stable.

+    supportsPassive = false;
     document.removeEventListener('test_event', query_function, query_options);
-    assert_equals(supportsCapture, internals.runtimeFlags.eventListenerOptionsEnabled);
+    assert_equals(supportsPassive, internals.runtimeFlags.eventListenerOptionsEnabled);
     t.done();
-}, "Supports Capture");
+}, "Supports Passive");
 </script>