Remove support for MSVC

sky/engine/wtf/NullPtr.h

Index: sky/engine/wtf/NullPtr.h
diff --git a/sky/engine/wtf/NullPtr.h b/sky/engine/wtf/NullPtr.h
index 9614104e97603a8abef9c8115c2d162e5e2cce6f..ccc9014fd57034d974b88bfca072013cec04dbc4 100644
--- a/sky/engine/wtf/NullPtr.h
+++ b/sky/engine/wtf/NullPtr.h
@@ -27,45 +27,6 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #ifndef NullPtr_h
 #define NullPtr_h
 
-// For compilers and standard libraries that do not yet include it, this adds the
-// nullptr_t type and nullptr object. They are defined in the same namespaces they
-// would be in compiler and library that had the support.
-
-#if COMPILER_SUPPORTS(CXX_NULLPTR) || defined(_LIBCPP_VERSION)
-
-// libstdc++ supports nullptr_t starting with gcc 4.6. STLport doesn't define it.
-#if (defined(__GLIBCXX__) && __GLIBCXX__ < 20110325) || defined(_STLPORT_VERSION)
-namespace std {
-typedef decltype(nullptr) nullptr_t;
-}
-#endif
-
-#else
-
-#include "wtf/WTFExport.h"
-
-namespace std {
-class nullptr_t {
-public:
-    // Required in order to create const nullptr_t objects without an
-    // explicit initializer in GCC 4.5, a la:
-    //
-    // const std::nullptr_t nullptr;
-    nullptr_t() { }
-
-    // Make nullptr convertible to any pointer type.
-    template<typename T> operator T*() const { return 0; }
-    // Make nullptr convertible to any member pointer type.
-    template<typename C, typename T> operator T C::*() { return 0; }
-private:
-    // Do not allow taking the address of nullptr.
-    void operator&();
-};
-}
-WTF_EXPORT extern const std::nullptr_t nullptr;
-
-#endif
-
 #define WTF_DISALLOW_CONSTRUCTION_FROM_ZERO(ClassName) \
     private: \
         ClassName(int) = delete