Add gmock into our dependencies.

third_party/boost/boost/type_traits/is_arithmetic.hpp

Index: third_party/boost/boost/type_traits/is_arithmetic.hpp
diff --git a/third_party/boost/boost/type_traits/is_arithmetic.hpp b/third_party/boost/boost/type_traits/is_arithmetic.hpp
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index 0000000000000000000000000000000000000000..be881c5fbe2305d2bdca4baeda1bd2d1604779b2
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+++ b/third_party/boost/boost/type_traits/is_arithmetic.hpp
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+
+//  (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_ARITHMETIC_HPP_INCLUDED
+#define BOOST_TT_IS_ARITHMETIC_HPP_INCLUDED
+
+#include <boost/type_traits/is_integral.hpp>
+#include <boost/type_traits/is_float.hpp>
+#include <boost/type_traits/detail/ice_or.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_arithmetic_impl
+{ 
+    BOOST_STATIC_CONSTANT(bool, value = 
+        (::boost::type_traits::ice_or< 
+            ::boost::is_integral<T>::value,
+            ::boost::is_float<T>::value
+        >::value)); 
+};
+
+} // namespace detail
+
+//* is a type T an arithmetic type described in the standard (3.9.1p8)
+BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_arithmetic,T,::boost::detail::is_arithmetic_impl<T>::value)
+
+} // namespace boost
+
+#include <boost/type_traits/detail/bool_trait_undef.hpp>
+
+#endif // BOOST_TT_IS_ARITHMETIC_HPP_INCLUDED