Run 300.twolf using benchmark binary

Change-Id: I116cabee87786439113b5b9a12dd26a2684e4adf
diff --git a/benchmarks/main.cc b/benchmarks/main.cc
index 44a0f2e..f2aaf49 100644
--- a/benchmarks/main.cc
+++ b/benchmarks/main.cc
@@ -48,6 +48,11 @@
   Bzip2Fixture() : SpecFixture("256.bzip2"){};
 };
 
+class TwolfFixture : public SpecFixture {
+ protected:
+  TwolfFixture() : SpecFixture("300.twolf"){};
+};
+
 }  // namespace
 
 std::string executableDir;
@@ -150,6 +155,16 @@
   }
 }
 
+BENCHMARK_F(TwolfFixture, 300_Twolf)(benchmark::State& st) {
+  while (st.KeepRunning()) {
+    const char* args[] = {"ref"};
+    if ((RunSpec(args, 1, NULL)) != 0) {
+      (std::string("Error while running benchmark: ") + strerror(errno))
+          .c_str();
+    }
+  }
+}
+
 int main(int argc, char* argv[]) {
   ::benchmark::Initialize(&argc, argv);
   google::InitGoogleLogging(argv[0]);