Add ability to time captured benchmarks (#1569)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1569

Added a `benchmark` function that takes a path representing a directory to read captures from. This is supplied by the caller due to annoyance with filesystem access in C++. This calls into timing code with <chrono> and prints it out to the console.

Reviewed By: NickGerleman

Differential Revision: D53104632

fbshipit-source-id: fe8bcb0a87198701865fb04193894591d2eff821

benchmark/Benchmark.h

@@ -7,11 +7,14 @@
 
 #pragma once
 
-#include <filesystem>
+#include <chrono>
 #include <string>
 
 namespace facebook::yoga {
 
-void generateBenchmark(const std::filesystem::path& capturePath);
+struct BenchmarkResult {
+  std::chrono::steady_clock::duration treeCreationDuration;
+  std::chrono::steady_clock::duration layoutDuration;
+};
 
 } // namespace facebook::yoga