Do not expose is_null API for time values in Blink

third_party/WebKit/Source/core/input/GestureManager.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 GestureManager_h
 #define GestureManager_h
 
 #include "core/CoreExport.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/HitTestRequest.h"
 #include "core/page/EventWithHitTestResults.h"
 #include "platform/PlatformEvent.h"
 #include "public/platform/WebInputEventResult.h"
+#include "wtf/Optional.h"
 
 namespace blink {
 
 class ScrollManager;
 class SelectionController;
 class PointerEventManager;
 class MouseEventManager;
 
 // This class takes care of gestures and delegating the action based on the
 // gesture to the responsible class.
@@ skipping 12 matching lines @@
   void clear();
 
   HitTestRequest::HitTestRequestType getHitTypeForGestureType(
       WebInputEvent::Type);
   WebInputEventResult handleGestureEventInFrame(
       const GestureEventWithHitTestResults&);
 
   // TODO(nzolghadr): This can probably be hidden and the related logic
   // be moved to this class (see crrev.com/112023010). Since that might cause
   // regression it's better to move that logic in another change.
-  TimeTicks getLastShowPressTimestamp() const;
+  WTF::Optional<WTF::TimeTicks> getLastShowPressTimestamp() const;
 
  private:
   WebInputEventResult handleGestureShowPress();
   WebInputEventResult handleGestureTapDown(
       const GestureEventWithHitTestResults&);
   WebInputEventResult handleGestureTap(const GestureEventWithHitTestResults&);
   WebInputEventResult handleGestureLongPress(
       const GestureEventWithHitTestResults&);
   WebInputEventResult handleGestureLongTap(
       const GestureEventWithHitTestResults&);
@@ skipping 16 matching lines @@
 
   // Set on GestureTapDown if the |pointerdown| event corresponding to the
   // triggering |touchstart| event was canceled. This suppresses mouse event
   // firing for the current gesture sequence (i.e. until next GestureTapDown).
   bool m_suppressMouseEventsFromGestures;
 
   bool m_longTapShouldInvokeContextMenu;
 
   const Member<SelectionController> m_selectionController;
 
-  TimeTicks m_lastShowPressTimestamp;
+  WTF::Optional<WTF::TimeTicks> m_lastShowPressTimestamp;
 };
 
 }  // namespace blink
 
 #endif  // GestureManager_h