Add gmock into our dependencies.

third_party/boost/boost/fusion/tuple/tuple_fwd.hpp

Index: third_party/boost/boost/fusion/tuple/tuple_fwd.hpp
diff --git a/third_party/boost/boost/fusion/tuple/tuple_fwd.hpp b/third_party/boost/boost/fusion/tuple/tuple_fwd.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..1a127cab104295151ca7cc8c243bb423146de5a8
--- /dev/null
+++ b/third_party/boost/boost/fusion/tuple/tuple_fwd.hpp
@@ -0,0 +1,24 @@
+/*=============================================================================
+    Copyright (c) 2005 Joel de Guzman
+
+    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)
+==============================================================================*/
+#if !defined(FUSION_TUPLE_FORWARD_10032005_0956)
+#define FUSION_TUPLE_FORWARD_10032005_0956
+
+#include <boost/fusion/container/vector/limits.hpp>
+#include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
+
+namespace boost { namespace fusion
+{
+    struct void_;
+
+    template <
+        BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(
+            FUSION_MAX_VECTOR_SIZE, typename T, void_)
+    >
+    struct tuple;
+}}
+
+#endif