Make touch events uncancelable during fling when they are on the current active scroll layer

cc/input/input_handler.h

Index: cc/input/input_handler.h
diff --git a/cc/input/input_handler.h b/cc/input/input_handler.h
index 9b96db789d1d03c4a5fc6fc655288ffb3ad0f0d1..063b6453ae94ece463675eb477d275ca4a8a55f9 100644
--- a/cc/input/input_handler.h
+++ b/cc/input/input_handler.h
@@ -188,9 +188,12 @@ class CC_EXPORT InputHandler {
   virtual EventListenerProperties GetEventListenerProperties(
       EventListenerClass event_class) const = 0;
 
-  // Whether the page should be given the opportunity to suppress scrolling by
-  // consuming touch events that started at |viewport_point|.
-  virtual bool DoTouchEventsBlockScrollAt(const gfx::Point& viewport_point) = 0;
+  // It returns the type of event listener at the given viewport point. Such as
+  // if the page has a touch handler or not, and whether the page should
+  // suppress scrolling by consuming touch events that started at
+  // |viewport_point|.
+  virtual EventListenerProperties EventListenerTypeForTouchStartAt(
+      const gfx::Point& viewport_point) = 0;
 
   // Calling CreateLatencyInfoSwapPromiseMonitor() to get a scoped
   // LatencyInfoSwapPromiseMonitor. During the life time of the