CMake build configurations

PiperOrigin-RevId: 273632973
diff --git a/cmake/DownloadGoogleBenchmark.cmake b/cmake/DownloadGoogleBenchmark.cmake
new file mode 100644
index 0000000..2ffc55f
--- /dev/null
+++ b/cmake/DownloadGoogleBenchmark.cmake
@@ -0,0 +1,23 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+# All rights reserved.
+#
+# Copyright 2019 Google LLC
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5 FATAL_ERROR)
+
+PROJECT(googlebenchmark-download NONE)
+
+INCLUDE(ExternalProject)
+ExternalProject_Add(googlebenchmark
+  URL https://github.com/google/benchmark/archive/v1.4.1.zip
+  URL_HASH SHA256=61ae07eb5d4a0b02753419eb17a82b7d322786bb36ab62bd3df331a4d47c00a7
+  SOURCE_DIR "${CMAKE_BINARY_DIR}/googlebenchmark-source"
+  BINARY_DIR "${CMAKE_BINARY_DIR}/googlebenchmark"
+  CONFIGURE_COMMAND ""
+  BUILD_COMMAND ""
+  INSTALL_COMMAND ""
+  TEST_COMMAND ""
+)