Check the root pointer events as well for capture

third_party/WebKit/Source/core/input/PointerEventManager.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/input/PointerEventManager.h"
 
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/shadow/FlatTreeTraversal.h"
 #include "core/events/MouseEvent.h"
 #include "core/frame/FrameView.h"
@@ skipping 645 matching lines @@
 }
 
 void PointerEventManager::releasePointerCapture(int pointerId) {
   m_pendingPointerCaptureTarget.remove(pointerId);
 }
 
 bool PointerEventManager::isActive(const int pointerId) const {
   return m_pointerEventFactory.isActive(pointerId);
 }
 
+// This function checks the type of the pointer event to be touch as touch
+// pointer events are the only ones that are directly dispatched from the main
+// page managers to their target (event if target is in an iframe) and only
+// those managers will keep track of these pointer events.
+bool PointerEventManager::isTouchPointerIdActiveOnFrame(
+    int pointerId,
+    LocalFrame* frame) const {
+  if (m_pointerEventFactory.getPointerType(pointerId) !=
+      WebPointerProperties::PointerType::Touch)
+    return false;
+  Node* lastNodeReceivingEvent =
+      m_nodeUnderPointer.contains(pointerId)
+          ? m_nodeUnderPointer.get(pointerId).target->toNode()
+          : nullptr;
+  return lastNodeReceivingEvent &&
+         lastNodeReceivingEvent->document().frame() == frame;
+}
+
 bool PointerEventManager::isAnyTouchActive() const {
   return m_touchEventManager->isAnyTouchActive();
 }
 
 bool PointerEventManager::primaryPointerdownCanceled(
     uint32_t uniqueTouchEventId) {
   // It's safe to assume that uniqueTouchEventIds won't wrap back to 0 from
   // 2^32-1 (>4.2 billion): even with a generous 100 unique ids per touch
   // sequence & one sequence per 10 second, it takes 13+ years to wrap back.
   while (!m_touchIdsForCanceledPointerdowns.isEmpty()) {
     uint32_t firstId = m_touchIdsForCanceledPointerdowns.first();
     if (firstId > uniqueTouchEventId)
       return false;
     m_touchIdsForCanceledPointerdowns.takeFirst();
     if (firstId == uniqueTouchEventId)
       return true;
   }
   return false;
 }
 
 EventTarget* PointerEventManager::getMouseCapturingNode() {
   return getCapturingNode(PointerEventFactory::s_mouseId);
 }
 
 }  // namespace blink