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

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 9bd3fc61babff2187b7095aa61138b5eb9ad2466..f9730b6a04086371d5030c31b229677c3b4b59c9 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -197,7 +197,8 @@ class CC_EXPORT LayerTreeHostImpl
       InputHandler::ScrollInputType type) const override;
   EventListenerProperties GetEventListenerProperties(
       EventListenerClass event_class) const override;
-  bool DoTouchEventsBlockScrollAt(const gfx::Point& viewport_port) override;
+  InputHandler::TouchStartHitResult DoTouchEventsBlockScrollAt(
+      const gfx::Point& viewport_port) override;
   std::unique_ptr<SwapPromiseMonitor> CreateLatencyInfoSwapPromiseMonitor(
       ui::LatencyInfo* latency) override;
   ScrollElasticityHelper* CreateScrollElasticityHelper() override;