Merge commit '55c543272667022808c0ca3ac8c6006a1337de9f' as 'third_party/google-benchmark'

Change-Id: Ie16a1447cdda711c30436e014cd41804b9fd7c5b
diff --git a/WORKSPACE b/WORKSPACE
index 58bac82..a9880e0 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -318,3 +318,9 @@
     name = "com_github_google_glog",
     path = "third_party/google-glog",
 )
+
+# External dependency: Google Benchmark; has no Bazel build.
+local_repository(
+    name = "com_github_google_benchmark",
+    path = "third_party/google-benchmark",
+)