Articulate the cancel behavior in the WebTouchEvent.

content/browser/renderer_host/input/input_router_impl.cc

Index: content/browser/renderer_host/input/input_router_impl.cc
diff --git a/content/browser/renderer_host/input/input_router_impl.cc b/content/browser/renderer_host/input/input_router_impl.cc
index 598e21747a928a468ffb9f3af15e7bbbcd347c06..bc1513e780fc3f90ca6a31f3922c8f7fb45fe844 100644
--- a/content/browser/renderer_host/input/input_router_impl.cc
+++ b/content/browser/renderer_host/input/input_router_impl.cc
@@ -369,8 +369,6 @@ void InputRouterImpl::OfferToHandlers(const WebInputEvent& input_event,
   if (OfferToClient(input_event, latency_info))
     return;
 
-  // Touch events should always indicate in the event whether they are
-  // cancelable (respect ACK disposition) or not except touchmove.
   bool should_block = WebInputEventTraits::ShouldBlockEventStream(input_event);
 
   OfferToRenderer(input_event, latency_info,
@@ -378,12 +376,6 @@ void InputRouterImpl::OfferToHandlers(const WebInputEvent& input_event,
                       ? InputEventDispatchType::DISPATCH_TYPE_BLOCKING
                       : InputEventDispatchType::DISPATCH_TYPE_NON_BLOCKING);
 
-  if (WebInputEvent::isTouchEventType(input_event.type) &&
-      input_event.type != WebInputEvent::TouchMove) {
-    const WebTouchEvent& touch = static_cast<const WebTouchEvent&>(input_event);
-    DCHECK_EQ(should_block, touch.cancelable);
-  }
-
   // Generate a synthetic ack if the event was sent so it doesn't block.
   if (!should_block) {
     ProcessInputEventAck(