Remove canScroll from WebMouseWheelEvent as it is unused now.

mojo/converters/blink/blink_input_events_type_converters.cc

Index: mojo/converters/blink/blink_input_events_type_converters.cc
diff --git a/mojo/converters/blink/blink_input_events_type_converters.cc b/mojo/converters/blink/blink_input_events_type_converters.cc
index 47d4a8fc6d9f7e0ec55569fb20dc5ee14a720b67..b8764d09ca789c5d669b43d1944fc17533e100d1 100644
--- a/mojo/converters/blink/blink_input_events_type_converters.cc
+++ b/mojo/converters/blink/blink_input_events_type_converters.cc
@@ -161,7 +161,6 @@ std::unique_ptr<blink::WebInputEvent> BuildWebMouseWheelEventFrom(
   // Add support for other wheel modes once ui::WheelEvent has support for them.
   web_event->hasPreciseScrollingDeltas = false;
   web_event->scrollByPage = false;
-  web_event->canScroll = true;
 
   return std::move(web_event);
 }