Fix use of uninitialized value in msan builds

third_party/WebKit/Source/core/events/PointerEventFactory.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 PointerEventFactory_h
 #define PointerEventFactory_h
 
 #include "core/CoreExport.h"
 #include "core/events/PointerEvent.h"
 #include "public/platform/WebPointerProperties.h"
@@ skipping 71 matching lines @@
         IncomingId() {}
         IncomingId(WebPointerProperties::PointerType pointerType,
             int rawId)
             : std::pair<int, int>(static_cast<int>(pointerType), rawId) {}
         int pointerType() const {return first;}
         int rawId() const {return second;}
     } IncomingId;
     typedef struct PointerAttributes {
         IncomingId incomingId;
         bool isActiveButtons;
-        PointerAttributes() {}
+        PointerAttributes()
+        : incomingId()
+        , isActiveButtons(false) {}
         PointerAttributes(IncomingId incomingId, unsigned isActiveButtons)
         : incomingId(incomingId)
         , isActiveButtons(isActiveButtons) {}
     } PointerAttributes;
 
     int addIdAndActiveButtons(const IncomingId, bool isActiveButtons);
     bool isPrimary(const int) const;
     void setIdTypeButtons(PointerEventInit&, const WebPointerProperties&,
         unsigned buttons);
     void setBubblesAndCancelable(PointerEventInit&, const AtomicString& type);
 
     // Creates pointerevents like boundary and capture events from another
     // pointerevent (i.e. up/down/move events).
     PointerEvent* createPointerEventFrom(
         PointerEvent*, const AtomicString&, EventTarget*);
 
     static const int s_invalidId;
 
     int m_currentId;
     HashMap<IncomingId, int, WTF::PairHash<int, int>, WTF::PairHashTraits<UnsignedHash, UnsignedHash>> m_pointerIncomingIdMapping;
     HashMap<int, PointerAttributes, WTF::IntHash<int>, UnsignedHash> m_pointerIdMapping;
     int m_primaryId[static_cast<int>(WebPointerProperties::PointerType::LastEntry) + 1];
     int m_idCount[static_cast<int>(WebPointerProperties::PointerType::LastEntry) + 1];
 };
 
 } // namespace blink
 
 #endif // PointerEventFactory_h