Add gmock into our dependencies.

third_party/boost/boost/preprocessor/detail/check.hpp

Index: third_party/boost/boost/preprocessor/detail/check.hpp
diff --git a/third_party/boost/boost/preprocessor/detail/check.hpp b/third_party/boost/boost/preprocessor/detail/check.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..63f8ff91665ae70cc36ba0e3e8551d24157f774b
--- /dev/null
+++ b/third_party/boost/boost/preprocessor/detail/check.hpp
@@ -0,0 +1,48 @@
+# /* **************************************************************************
+#  *                                                                          *
+#  *     (C) Copyright Paul Mensonides 2002.
+#  *     Distributed under 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 for most recent version. */
+#
+# ifndef BOOST_PREPROCESSOR_DETAIL_CHECK_HPP
+# define BOOST_PREPROCESSOR_DETAIL_CHECK_HPP
+#
+# include <boost/preprocessor/cat.hpp>
+# include <boost/preprocessor/config/config.hpp>
+#
+# /* BOOST_PP_CHECK */
+#
+# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MWCC()
+#    define BOOST_PP_CHECK(x, type) BOOST_PP_CHECK_D(x, type)
+# else
+#    define BOOST_PP_CHECK(x, type) BOOST_PP_CHECK_OO((x, type))
+#    define BOOST_PP_CHECK_OO(par) BOOST_PP_CHECK_D ## par
+# endif
+#
+# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MSVC() && ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_DMC()
+#    define BOOST_PP_CHECK_D(x, type) BOOST_PP_CHECK_1(BOOST_PP_CAT(BOOST_PP_CHECK_RESULT_, type x))
+#    define BOOST_PP_CHECK_1(chk) BOOST_PP_CHECK_2(chk)
+#    define BOOST_PP_CHECK_2(res, _) res
+# elif BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MSVC()
+#    define BOOST_PP_CHECK_D(x, type) BOOST_PP_CHECK_1(type x)
+#    define BOOST_PP_CHECK_1(chk) BOOST_PP_CHECK_2(chk)
+#    define BOOST_PP_CHECK_2(chk) BOOST_PP_CHECK_3((BOOST_PP_CHECK_RESULT_ ## chk))
+#    define BOOST_PP_CHECK_3(im) BOOST_PP_CHECK_5(BOOST_PP_CHECK_4 im)
+#    define BOOST_PP_CHECK_4(res, _) res
+#    define BOOST_PP_CHECK_5(res) res
+# else /* DMC */
+#    define BOOST_PP_CHECK_D(x, type) BOOST_PP_CHECK_OO((type x))
+#    define BOOST_PP_CHECK_OO(par) BOOST_PP_CHECK_0 ## par
+#    define BOOST_PP_CHECK_0(chk) BOOST_PP_CHECK_1(BOOST_PP_CAT(BOOST_PP_CHECK_RESULT_, chk))
+#    define BOOST_PP_CHECK_1(chk) BOOST_PP_CHECK_2(chk)
+#    define BOOST_PP_CHECK_2(res, _) res
+# endif
+#
+# define BOOST_PP_CHECK_RESULT_1 1, BOOST_PP_NIL
+#
+# endif