Add gmock into our dependencies.

third_party/boost/boost/preprocessor/seq/seq.hpp

Index: third_party/boost/boost/preprocessor/seq/seq.hpp
diff --git a/third_party/boost/boost/preprocessor/seq/seq.hpp b/third_party/boost/boost/preprocessor/seq/seq.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..f5ca84c6f394716283546931ac4377ab79981c51
--- /dev/null
+++ b/third_party/boost/boost/preprocessor/seq/seq.hpp
@@ -0,0 +1,44 @@
+# /* **************************************************************************
+#  *                                                                          *
+#  *     (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_SEQ_SEQ_HPP
+# define BOOST_PREPROCESSOR_SEQ_SEQ_HPP
+#
+# include <boost/preprocessor/config/config.hpp>
+# include <boost/preprocessor/seq/elem.hpp>
+#
+# /* BOOST_PP_SEQ_HEAD */
+#
+# define BOOST_PP_SEQ_HEAD(seq) BOOST_PP_SEQ_ELEM(0, seq)
+#
+# /* BOOST_PP_SEQ_TAIL */
+#
+# if BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MWCC()
+#    define BOOST_PP_SEQ_TAIL(seq) BOOST_PP_SEQ_TAIL_1((seq))
+#    define BOOST_PP_SEQ_TAIL_1(par) BOOST_PP_SEQ_TAIL_2 ## par
+#    define BOOST_PP_SEQ_TAIL_2(seq) BOOST_PP_SEQ_TAIL_I ## seq
+# elif BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MSVC()
+#    define BOOST_PP_SEQ_TAIL(seq) BOOST_PP_SEQ_TAIL_ID(BOOST_PP_SEQ_TAIL_I seq)
+#    define BOOST_PP_SEQ_TAIL_ID(id) id
+# elif BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
+#    define BOOST_PP_SEQ_TAIL(seq) BOOST_PP_SEQ_TAIL_D(seq)
+#    define BOOST_PP_SEQ_TAIL_D(seq) BOOST_PP_SEQ_TAIL_I seq
+# else
+#    define BOOST_PP_SEQ_TAIL(seq) BOOST_PP_SEQ_TAIL_I seq
+# endif
+#
+# define BOOST_PP_SEQ_TAIL_I(x)
+#
+# /* BOOST_PP_SEQ_NIL */
+#
+# define BOOST_PP_SEQ_NIL(x) (x)
+#
+# endif