WTF/std normalization: replace WTF::Vector::last with ::back

third_party/WebKit/Source/core/dom/shadow/InsertionPoint.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 279 matching lines @@
     ElementShadow* shadow = shadowWhereNodeCanBeDistributedForV0(*current);
     if (!shadow || shadow->isV1() || shadow == lastElementShadow)
       return;
     lastElementShadow = shadow;
     const DestinationInsertionPoints* insertionPoints =
         shadow->v0().destinationInsertionPointsFor(&node);
     if (!insertionPoints)
       return;
     for (size_t i = 0; i < insertionPoints->size(); ++i)
       results.append(insertionPoints->at(i).get());
-    DCHECK_NE(current, insertionPoints->last().get());
-    current = insertionPoints->last().get();
+    DCHECK_NE(current, insertionPoints->back().get());
+    current = insertionPoints->back().get();
   }
 }
 
 }  // namespace blink