Add gmock into our dependencies.

third_party/boost/boost/preprocessor/list/append.hpp

Index: third_party/boost/boost/preprocessor/list/append.hpp
diff --git a/third_party/boost/boost/preprocessor/list/append.hpp b/third_party/boost/boost/preprocessor/list/append.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..26e9d74e094fefe853e51093120a5c78517ddf5c
--- /dev/null
+++ b/third_party/boost/boost/preprocessor/list/append.hpp
@@ -0,0 +1,40 @@
+# /* Copyright (C) 2001
+#  * Housemarque Oy
+#  * http://www.housemarque.com
+#  *
+#  * 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)
+#  */
+#
+# /* Revised by Paul Mensonides (2002) */
+#
+# /* See http://www.boost.org for most recent version. */
+#
+# ifndef BOOST_PREPROCESSOR_LIST_APPEND_HPP
+# define BOOST_PREPROCESSOR_LIST_APPEND_HPP
+#
+# include <boost/preprocessor/config/config.hpp>
+# include <boost/preprocessor/list/fold_right.hpp>
+#
+# /* BOOST_PP_LIST_APPEND */
+#
+# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
+#    define BOOST_PP_LIST_APPEND(a, b) BOOST_PP_LIST_FOLD_RIGHT(BOOST_PP_LIST_APPEND_O, b, a)
+# else
+#    define BOOST_PP_LIST_APPEND(a, b) BOOST_PP_LIST_APPEND_I(a, b)
+#    define BOOST_PP_LIST_APPEND_I(a, b) BOOST_PP_LIST_FOLD_RIGHT(BOOST_PP_LIST_APPEND_O, b, a)
+# endif
+#
+# define BOOST_PP_LIST_APPEND_O(d, s, x) (x, s)
+#
+# /* BOOST_PP_LIST_APPEND_D */
+#
+# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
+#    define BOOST_PP_LIST_APPEND_D(d, a, b) BOOST_PP_LIST_FOLD_RIGHT_ ## d(BOOST_PP_LIST_APPEND_O, b, a)
+# else
+#    define BOOST_PP_LIST_APPEND_D(d, a, b) BOOST_PP_LIST_APPEND_D_I(d, a, b)
+#    define BOOST_PP_LIST_APPEND_D_I(d, a, b) BOOST_PP_LIST_FOLD_RIGHT_ ## d(BOOST_PP_LIST_APPEND_O, b, a)
+# endif
+#
+# endif