Touch Action could cause wheel gestures to be filtered.

content/browser/renderer_host/input/input_router_impl_unittest.cc

Index: content/browser/renderer_host/input/input_router_impl_unittest.cc
diff --git a/content/browser/renderer_host/input/input_router_impl_unittest.cc b/content/browser/renderer_host/input/input_router_impl_unittest.cc
index 4409e94170fadebfa9989b6082eaf11b6acb69bf..d8ce0648722b12473c3b02422a892977a2f02499 100644
--- a/content/browser/renderer_host/input/input_router_impl_unittest.cc
+++ b/content/browser/renderer_host/input/input_router_impl_unittest.cc
@@ -2213,8 +2213,8 @@ TEST_F(InputRouterImplScaleGestureEventTest, GestureScrollUpdate) {
 }
 
 TEST_F(InputRouterImplScaleGestureEventTest, GestureScrollBegin) {
-  SimulateGestureEvent(
-      SyntheticWebGestureEventBuilder::BuildScrollBegin(10.f, 20.f));
+  SimulateGestureEvent(SyntheticWebGestureEventBuilder::BuildScrollBegin(
+      10.f, 20.f, blink::WebGestureDeviceTouchscreen));
   const WebGestureEvent* sent_event = GetSentWebInputEvent<WebGestureEvent>();
   EXPECT_EQ(20.f, sent_event->data.scrollBegin.deltaXHint);
   EXPECT_EQ(40.f, sent_event->data.scrollBegin.deltaYHint);