Added PointerEvent.hasPointerCapture API.

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 742 matching lines @@
     // the capture. Note that this might be different from
     // |m_pointercaptureTarget|. |m_pointercaptureTarget| holds the element
     // that had the capture until now and has been receiving the pointerevents
     // but |m_pendingPointerCaptureTarget| indicated the element that gets the
     // very next pointer event. They will be the same if there was no change in
     // capturing of a particular |pointerId|. See crbug.com/614481.
     if (m_pendingPointerCaptureTarget.get(pointerId) == target)
         releasePointerCapture(pointerId);
 }
 
+bool PointerEventManager::hasPointerCapture(int pointerId, EventTarget* target)
+{
+    return m_pendingPointerCaptureTarget.get(pointerId) == target;
+}
+
 void PointerEventManager::releasePointerCapture(int pointerId)
 {
     m_pendingPointerCaptureTarget.remove(pointerId);
 }
 
 bool PointerEventManager::isActive(const int pointerId) const
 {
     return m_pointerEventFactory.isActive(pointerId);
 }
 
@@ skipping 27 matching lines @@
 {
     visitor->trace(m_frame);
     visitor->trace(m_nodeUnderPointer);
     visitor->trace(m_pointerCaptureTarget);
     visitor->trace(m_pendingPointerCaptureTarget);
     visitor->trace(m_touchEventManager);
 }
 
 
 } // namespace blink