Add preventPropagation bit to GestureScrollUpdate event

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index 43018563ffb62a910bb6699f686465e66ea7f171..1d7c92444b6cff8fb86d5ce9b37554638a424f02 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -2465,7 +2465,8 @@ bool EventHandler::handleGestureScrollUpdate(const PlatformGestureEvent& gesture
     RefPtrWillBeRawPtr<FrameView> protector(m_frame->view());
 
     Node* stopNode = nullptr;
-    bool scrollShouldNotPropagate = gestureEvent.type() == PlatformEvent::GestureScrollUpdateWithoutPropagation;
+    bool scrollShouldNotPropagate = gestureEvent.type() == PlatformEvent::GestureScrollUpdateWithoutPropagation
+        || (gestureEvent.type() == PlatformEvent::GestureScrollUpdate && gestureEvent.preventPropagation());
 
     // Try to send the event to the correct view.
     if (passScrollGestureEventToWidget(gestureEvent, renderer)) {