Remove a VS2010 workaround.

Source/wtf/Vector.h

 /*
  *  Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 745 matching lines @@
             return *this;
 
         if (size() > other.size())
             shrink(other.size());
         else if (other.size() > capacity()) {
             clear();
             reserveCapacity(other.size());
             ASSERT(begin());
         }
 
-// Works around an assert in VS2010. See https://connect.microsoft.com/VisualStudio/feedback/details/558044/std-copy-should-not-check-dest-when-first-last
-#if COMPILER(MSVC) && defined(_ITERATOR_DEBUG_LEVEL) && _ITERATOR_DEBUG_LEVEL
-        if (!begin())
-            return *this;
-#endif
-
         std::copy(other.begin(), other.begin() + size(), begin());
         TypeOperations::uninitializedCopy(other.begin() + size(), other.end(), end());
         m_size = other.size();
 
         return *this;
     }
 
     inline bool typelessPointersAreEqual(const void* a, const void* b) { return a == b; }
 
     template<typename T, size_t inlineCapacity, typename Allocator>
     template<size_t otherCapacity>
     Vector<T, inlineCapacity, Allocator>& Vector<T, inlineCapacity, Allocator>::operator=(const Vector<T, otherCapacity, Allocator>& other)
     {
         // If the inline capacities match, we should call the more specific
         // template.  If the inline capacities don't match, the two objects
         // shouldn't be allocated the same address.
         ASSERT(!typelessPointersAreEqual(&other, this));
 
         if (size() > other.size())
             shrink(other.size());
         else if (other.size() > capacity()) {
             clear();
             reserveCapacity(other.size());
             ASSERT(begin());
         }
 
-// Works around an assert in VS2010. See https://connect.microsoft.com/VisualStudio/feedback/details/558044/std-copy-should-not-check-dest-when-first-last
-#if COMPILER(MSVC) && defined(_ITERATOR_DEBUG_LEVEL) && _ITERATOR_DEBUG_LEVEL
-        if (!begin())
-            return *this;
-#endif
-
         std::copy(other.begin(), other.begin() + size(), begin());
         TypeOperations::uninitializedCopy(other.begin() + size(), other.end(), end());
         m_size = other.size();
 
         return *this;
     }
 
 #if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES)
     template<typename T, size_t inlineCapacity, typename Allocator>
     Vector<T, inlineCapacity, Allocator>::Vector(Vector<T, inlineCapacity, Allocator>&& other)
@@ skipping 393 matching lines @@
     struct NeedsTracing<Vector<T, N> > {
         static const bool value = false;
     };
 #endif
 
 } // namespace WTF
 
 using WTF::Vector;
 
 #endif // WTF_Vector_h