Fabric: Synthetic benchmarks for prop parsing infra

Summary:
And, btw, the tests show that performance of that is not so great:
```
Running /Users/shergin/fbsource/fbobjc/buck-out/cells/fbsource/gen/xplat/js/react-native-github/ReactCommon/fabric/core/benchmarks
Run on (12 X 2900 MHz CPU s)
CPU Caches:
  L1 Data 32K (x6)
  L1 Instruction 32K (x6)
  L2 Unified 262K (x6)
  L3 Unified 12582K (x1)
--------------------------------------------------------------------------------------------
Benchmark                                                     Time           CPU Iterations
--------------------------------------------------------------------------------------------
propParsingUsingComponentDescriptor                       79630 ns      77991 ns       8864
propParsingUsingComponentDescriptorWithNoSourceProps      70200 ns      69099 ns       8362
```

Which means 70ms per 1000 prop parsing processes.

Reviewed By: JoshuaGross, mdvacca

Differential Revision: D15608677

fbshipit-source-id: ed4feca489e1243adc73de4741c287256c3aaec3

ReactCommon/fabric/core/BUCK

@@ -1,3 +1,4 @@
+load("@fbsource//tools/build_defs:fb_xplat_cxx_binary.bzl", "fb_xplat_cxx_binary")
 load("@fbsource//tools/build_defs/apple:flag_defs.bzl", "get_debug_preprocessor_flags")
 load(
     "//tools/build_defs/oss:rn_defs.bzl",
@@ -70,8 +71,8 @@ rn_xplat_cxx_library(
 
 fb_xplat_cxx_test(
     name = "tests",
-    srcs = glob(["tests/**/*.cpp"]),
-    headers = glob(["tests/**/*.h"]),
+    srcs = glob(["tests/*.cpp"]),
+    headers = glob(["tests/*.h"]),
     compiler_flags = [
         "-fexceptions",
         "-frtti",
@@ -86,3 +87,26 @@ fb_xplat_cxx_test(
         ":core",
     ],
 )
+
+fb_xplat_cxx_binary(
+    name = "benchmarks",
+    srcs = glob(["tests/benchmarks/*.cpp"]),
+    compiler_flags = [
+        "-fexceptions",
+        "-frtti",
+        "-std=c++14",
+        "-Wall",
+        "-Wno-unused-variable",
+    ],
+    contacts = ["oncall+react_native@xmail.facebook.com"],
+    fbobjc_compiler_flags = APPLE_COMPILER_FLAGS,
+    fbobjc_preprocessor_flags = get_debug_preprocessor_flags() + get_apple_inspector_flags(),
+    platforms = (ANDROID, APPLE, CXX),
+    visibility = ["PUBLIC"],
+    deps = [
+        "fbsource//xplat/third-party/benchmark:benchmark",
+        react_native_xplat_target("utils:utils"),
+        react_native_xplat_target("fabric/components/view:view"),
+        ":core",
+    ],
+)

ReactCommon/fabric/core/tests/benchmarks/RawPropsBenchmark.cpp

@@ -0,0 +1,80 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <benchmark/benchmark.h>
+#include <folly/dynamic.h>
+#include <folly/json.h>
+#include <react/components/view/ViewComponentDescriptor.h>
+#include <react/core/EventDispatcher.h>
+#include <react/core/RawProps.h>
+#include <react/utils/ContextContainer.h>
+#include <exception>
+#include <string>
+
+namespace facebook {
+namespace react {
+
+auto contextContainer = std::make_shared<ContextContainer const>();
+auto eventDispatcher = std::shared_ptr<EventDispatcher>{nullptr};
+auto viewComponentDescriptor =
+    ViewComponentDescriptor(eventDispatcher, contextContainer);
+
+auto emptyPropsDynamic = folly::parseJson("{}");
+auto propsString = std::string{
+    "{\"flex\": 1, \"padding\": 10, \"position\": \"absolute\", \"display\": \"none\", \"nativeID\": \"some-id\", \"direction\": \"rtl\"}"};
+auto propsDynamic = folly::parseJson(propsString);
+auto propsStringWithSomeUnsupportedProps = std::string{
+    "{\"someName1\": 1, \"someName2\": 10, \"someName3\": \"absolute\", \"someName4\": \"none\", \"someName5\": \"some-id\", \"someName6\": \"rtl\"}"};
+auto unsupportedPropsDynamic =
+    folly::parseJson(propsStringWithSomeUnsupportedProps);
+
+auto sourceProps = ViewProps{};
+auto sharedSourceProps = ViewShadowNode::defaultSharedProps();
+
+static void emptyPropCreation(benchmark::State &state) {
+  for (auto _ : state) {
+    ViewProps{};
+  }
+}
+BENCHMARK(emptyPropCreation);
+
+static void propParsingEmptyRawProps(benchmark::State &state) {
+  for (auto _ : state) {
+    viewComponentDescriptor.cloneProps(
+        sharedSourceProps, RawProps{emptyPropsDynamic});
+  }
+}
+BENCHMARK(propParsingEmptyRawProps);
+
+static void propParsingRegularRawProps(benchmark::State &state) {
+  for (auto _ : state) {
+    viewComponentDescriptor.cloneProps(
+        sharedSourceProps, RawProps{propsDynamic});
+  }
+}
+BENCHMARK(propParsingRegularRawProps);
+
+static void propParsingUnsupportedRawProps(benchmark::State &state) {
+  for (auto _ : state) {
+    viewComponentDescriptor.cloneProps(
+        sharedSourceProps, RawProps{unsupportedPropsDynamic});
+  }
+}
+BENCHMARK(propParsingUnsupportedRawProps);
+
+static void propParsingRegularRawPropsWithNoSourceProps(
+    benchmark::State &state) {
+  for (auto _ : state) {
+    viewComponentDescriptor.cloneProps(nullptr, RawProps{propsDynamic});
+  }
+}
+BENCHMARK(propParsingRegularRawPropsWithNoSourceProps);
+
+} // namespace react
+} // namespace facebook
+
+BENCHMARK_MAIN();