Adding Google benchmarking library.

third_party/google_benchmark/test/fixture_test.cc

Index: third_party/google_benchmark/test/fixture_test.cc
diff --git a/third_party/google_benchmark/test/fixture_test.cc b/third_party/google_benchmark/test/fixture_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bbc2f9579023c8889833eb063ffab739a8e84eb9
--- /dev/null
+++ b/third_party/google_benchmark/test/fixture_test.cc
@@ -0,0 +1,49 @@
+
+#include "benchmark/benchmark.h"
+
+#include <cassert>
+#include <memory>
+
+class MyFixture : public ::benchmark::Fixture {
+ public:
+  void SetUp(const ::benchmark::State& state) {
+    if (state.thread_index == 0) {
+      assert(data.get() == nullptr);
+      data.reset(new int(42));
+    }
+  }
+
+  void TearDown(const ::benchmark::State& state) {
+    if (state.thread_index == 0) {
+      assert(data.get() != nullptr);
+      data.reset();
+    }
+  }
+
+  ~MyFixture() { assert(data == nullptr); }
+
+  std::unique_ptr<int> data;
+};
+
+BENCHMARK_F(MyFixture, Foo)(benchmark::State &st) {
+  assert(data.get() != nullptr);
+  assert(*data == 42);
+  while (st.KeepRunning()) {
+  }
+}
+
+BENCHMARK_DEFINE_F(MyFixture, Bar)(benchmark::State& st) {
+  if (st.thread_index == 0) {
+    assert(data.get() != nullptr);
+    assert(*data == 42);
+  }
+  while (st.KeepRunning()) {
+    assert(data.get() != nullptr);
+    assert(*data == 42);
+  }
+  st.SetItemsProcessed(st.range(0));
+}
+BENCHMARK_REGISTER_F(MyFixture, Bar)->Arg(42);
+BENCHMARK_REGISTER_F(MyFixture, Bar)->Arg(42)->ThreadPerCpu();
+
+BENCHMARK_MAIN()