Do not expose is_null API for time values in Blink

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 1645 matching lines @@
   ASSERT(m_frame == m_frame->localFrameRoot());
   // Scrolling events get hit tested per frame (like wheel events do).
   ASSERT(!gestureEvent.isScrollEvent());
 
   HitTestRequest::HitTestRequestType hitType =
       m_gestureManager->getHitTypeForGestureType(gestureEvent.type());
   TimeDelta activeInterval;
   bool shouldKeepActiveForMinInterval = false;
   if (readOnly) {
     hitType |= HitTestRequest::ReadOnly;
-  } else if (gestureEvent.type() == WebInputEvent::GestureTap) {
+  } else if (gestureEvent.type() == WebInputEvent::GestureTap &&
+             m_gestureManager->getLastShowPressTimestamp()) {

[esprehn, 2017/02/01 05:25:20]

getLastShowPressTimestamp() I suppose is cheap enough to call twice here?

[majidvp, 2017/02/03 15:42:27]

It is cheap. Just a plain data member access.

     // If the Tap is received very shortly after ShowPress, we want to
     // delay clearing of the active state so that it's visible to the user
     // for at least a couple of frames.
-    activeInterval =
-        TimeTicks::Now() - m_gestureManager->getLastShowPressTimestamp();
-    shouldKeepActiveForMinInterval =
-        !m_gestureManager->getLastShowPressTimestamp().isNull() &&
-        activeInterval < minimumActiveInterval;
+    activeInterval = TimeTicks::Now() -
+                     m_gestureManager->getLastShowPressTimestamp().value();
+    shouldKeepActiveForMinInterval = activeInterval < minimumActiveInterval;
     if (shouldKeepActiveForMinInterval)
       hitType |= HitTestRequest::ReadOnly;
   }
 
   GestureEventWithHitTestResults eventWithHitTestResults =
       hitTestResultForGestureEvent(gestureEvent, hitType);
   // Now apply hover/active state to the final target.
   HitTestRequest request(hitType | HitTestRequest::AllowChildFrameContent);
   if (!request.readOnly())
     updateGestureHoverActiveState(
@@ skipping 440 matching lines @@
 }
 
 FrameHost* EventHandler::frameHost() const {
   if (!m_frame->page())
     return nullptr;
 
   return &m_frame->page()->frameHost();
 }
 
 }  // namespace blink