Simplify the usage of PositionWithAffinity

third_party/WebKit/Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 1202 matching lines @@
     return HeapVector<Member<Element>>();
   return TreeScope::elementsFromPoint(x, y);
 }
 
 Range* Document::caretRangeFromPoint(int x, int y) {
   if (layoutViewItem().isNull())
     return nullptr;
 
   HitTestResult result = hitTestInDocument(this, x, y);
   PositionWithAffinity positionWithAffinity = result.position();
-  if (positionWithAffinity.position().isNull())
+  if (positionWithAffinity.isNull())
     return nullptr;
 
   Position rangeCompliantPosition =
       positionWithAffinity.position().parentAnchoredEquivalent();
   return Range::createAdjustedToTreeScope(*this, rangeCompliantPosition);
 }
 
 Element* Document::scrollingElement() {
   if (RuntimeEnabledFeatures::scrollTopLeftInteropEnabled()) {
     if (inQuirksMode()) {
@@ skipping 5167 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->url().getString().utf8().data());
 }
 #endif