Add gmock into our dependencies.

third_party/boost/boost/fusion/support/sequence_base.hpp

Index: third_party/boost/boost/fusion/support/sequence_base.hpp
diff --git a/third_party/boost/boost/fusion/support/sequence_base.hpp b/third_party/boost/boost/fusion/support/sequence_base.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..1d436ef165f111b103ba253742672028d3f06200
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+++ b/third_party/boost/boost/fusion/support/sequence_base.hpp
@@ -0,0 +1,45 @@
+/*=============================================================================
+    Copyright (c) 2001-2006 Joel de Guzman
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_SEQUENCE_BASE_04182005_0737)
+#define FUSION_SEQUENCE_BASE_04182005_0737
+
+#include <boost/mpl/begin_end_fwd.hpp>
+
+namespace boost { namespace fusion
+{
+    struct sequence_root {};
+
+    template <typename Sequence>
+    struct sequence_base : sequence_root
+    {
+        Sequence const&
+        derived() const
+        {
+            return static_cast<Sequence const&>(*this);
+        }
+
+        Sequence&
+        derived()
+        {
+            return static_cast<Sequence&>(*this);
+        }
+    };
+
+    struct fusion_sequence_tag;
+}}
+
+namespace boost { namespace mpl
+{
+    // Deliberately break mpl::begin, so it doesn't lie that a Fusion sequence
+    // is not an MPL sequence by returning mpl::void_.
+    // In other words: Fusion Sequences are always MPL Sequences, but they can
+    // be incompletely defined.
+    template<> struct begin_impl< boost::fusion::fusion_sequence_tag >;
+}}
+
+#endif