Add gmock into our dependencies.

third_party/boost/boost/type_traits/detail/ice_not.hpp

Index: third_party/boost/boost/type_traits/detail/ice_not.hpp
diff --git a/third_party/boost/boost/type_traits/detail/ice_not.hpp b/third_party/boost/boost/type_traits/detail/ice_not.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..ee1dca0ecd5405ffbcbeddb50168730083f95b52
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+++ b/third_party/boost/boost/type_traits/detail/ice_not.hpp
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+//  (C) Copyright John Maddock and Steve Cleary 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_DETAIL_ICE_NOT_HPP_INCLUDED
+#define BOOST_TT_DETAIL_ICE_NOT_HPP_INCLUDED
+
+#include <boost/config.hpp>
+
+namespace boost {
+namespace type_traits {
+
+template <bool b>
+struct ice_not
+{
+    BOOST_STATIC_CONSTANT(bool, value = true);
+};
+
+template <>
+struct ice_not<true>
+{
+    BOOST_STATIC_CONSTANT(bool, value = false);
+};
+
+} // namespace type_traits
+} // namespace boost
+
+#endif // BOOST_TT_DETAIL_ICE_NOT_HPP_INCLUDED