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

third_party/WebKit/Source/core/frame/EventHandlerRegistry.h

Index: third_party/WebKit/Source/core/frame/EventHandlerRegistry.h
diff --git a/third_party/WebKit/Source/core/frame/EventHandlerRegistry.h b/third_party/WebKit/Source/core/frame/EventHandlerRegistry.h
index 4d1dd0882a33c5f0aa9ee129ac6a517517c0a885..f9d273d7a9d8ec2825cb12718b10674be7da9cf8 100644
--- a/third_party/WebKit/Source/core/frame/EventHandlerRegistry.h
+++ b/third_party/WebKit/Source/core/frame/EventHandlerRegistry.h
@@ -33,6 +33,8 @@ public:
         WheelEventPassive,
         TouchEventBlocking,
         TouchEventPassive,

[Rick Byers, 2016/04/14 01:41:41]

Please rename these to TouchStartOrMove* for symmetry and to avoid confusion.

[dtapuska, 2016/04/14 01:49:10]

Do you want the WebEventListenerClass enum renamed too?

[dtapuska, 2016/04/14 14:41:11]

Done.

+        TouchEndOrCancelEventBlocking,
+        TouchEndOrCancelEventPassive,
 #if ENABLE(ASSERT)
         // Additional event categories for verifying handler tracking logic.
         EventsForTesting,
@@ -80,6 +82,9 @@ private:
     // removed an existing one.
     bool updateEventHandlerTargets(ChangeOperation, EventHandlerClass, EventTarget*);
 
+    // Update whether we have any touch handler or not.
+    void updateHasTouchEventListeners();
+
     // Called on the EventHandlerRegistry of the root Document to notify
     // clients when we have added the first handler or removed the last one for
     // a given event class. |hasActiveHandlers| can be used to distinguish