Add gmock into our dependencies.

third_party/boost/boost/type_traits/is_stateless.hpp

Index: third_party/boost/boost/type_traits/is_stateless.hpp
diff --git a/third_party/boost/boost/type_traits/is_stateless.hpp b/third_party/boost/boost/type_traits/is_stateless.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..d8d40635fe220d3bb9a1dde2bf3666a50923b01b
--- /dev/null
+++ b/third_party/boost/boost/type_traits/is_stateless.hpp
@@ -0,0 +1,48 @@
+
+//  (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
+//  Use, modification and distribution are subject to the Boost Software License,
+//  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt).
+//
+//  See http://www.boost.org/libs/type_traits for most recent version including documentation.
+
+#ifndef BOOST_TT_IS_STATELESS_HPP_INCLUDED
+#define BOOST_TT_IS_STATELESS_HPP_INCLUDED
+
+#include <boost/type_traits/has_trivial_constructor.hpp>
+#include <boost/type_traits/has_trivial_copy.hpp>
+#include <boost/type_traits/has_trivial_destructor.hpp>
+#include <boost/type_traits/is_class.hpp>
+#include <boost/type_traits/is_empty.hpp>
+#include <boost/type_traits/detail/ice_and.hpp>
+#include <boost/config.hpp>
+
+// should be the last #include
+#include <boost/type_traits/detail/bool_trait_def.hpp>
+
+namespace boost {
+
+namespace detail {
+
+template <typename T>
+struct is_stateless_impl
+{
+  BOOST_STATIC_CONSTANT(bool, value = 
+    (::boost::type_traits::ice_and<
+       ::boost::has_trivial_constructor<T>::value,
+       ::boost::has_trivial_copy<T>::value,
+       ::boost::has_trivial_destructor<T>::value,
+       ::boost::is_class<T>::value,
+       ::boost::is_empty<T>::value
+     >::value));
+};
+
+} // namespace detail
+
+BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_stateless,T,::boost::detail::is_stateless_impl<T>::value)
+
+} // namespace boost
+
+#include <boost/type_traits/detail/bool_trait_undef.hpp>
+
+#endif // BOOST_TT_IS_STATELESS_HPP_INCLUDED