Add UseCounter for setPointerCapture outside dispatch

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

 // 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.
 
 #ifndef PointerEventManager_h
 #define PointerEventManager_h
 
 #include "core/CoreExport.h"
 #include "core/events/PointerEvent.h"
 #include "core/events/PointerEventFactory.h"
@@ skipping 205 matching lines @@
                   WTF::IntHash<int>,
                   WTF::UnsignedWithZeroKeyHashTraits<int>>;
   NodeUnderPointerMap m_nodeUnderPointer;
 
   PointerCapturingMap m_pointerCaptureTarget;
   PointerCapturingMap m_pendingPointerCaptureTarget;
 
   PointerEventFactory m_pointerEventFactory;
   Member<TouchEventManager> m_touchEventManager;
   Member<MouseEventManager> m_mouseEventManager;
+
+  // The pointerId of the PointerEvent currently being dispatched within this
+  // frame or 0 if none.
+  int m_dispatchingPointerId;
 };
 
 }  // namespace blink
 
 #endif  // PointerEventManager_h