Add micro-benchmark for Proxy get property

Bug: v8:6559, v8:6557
Change-Id: Ide0114a5cdcce3cf948a070465460662c56bad8d
Reviewed-on: https://chromium-review.googlesource.com/577527
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Franziska Hinkelmann <franzih@chromium.org>
Commit-Queue: Maya Lekova <mslekova@google.com>
Cr-Commit-Position: refs/heads/master@{#46757}

test/js-perf-test/JSTests.json

@@ -22,7 +22,9 @@
         {"name": "CallProxyWithoutTrap"},
         {"name": "CallProxyWithTrap"},
         {"name": "ConstructProxyWithoutTrap"},
-        {"name": "ConstructProxyWithTrap"}
+        {"name": "ConstructProxyWithTrap"},
+        {"name": "GetPropertyOfProxyWithoutTrap"},
+        {"name": "GetPropertyOfProxyWithTrap"}
       ]
     },
     {

test/js-perf-test/Proxies/proxies.js

@@ -42,7 +42,7 @@ newBenchmark("ProxyConstructorWithClass", {
 
 // ----------------------------------------------------------------------------
 
-var obj = {};
+let obj = {};
 
 newBenchmark("ProxyConstructorWithObject", {
   setup() { },
@@ -151,3 +151,44 @@ newBenchmark("ConstructProxyWithTrap", {
     return instance instanceof MyClass;
   }
 });
+
+// ----------------------------------------------------------------------------
+
+obj = {
+  prop: SOME_NUMBER
+}
+let value;
+
+newBenchmark("GetPropertyOfProxyWithoutTrap", {
+  setup() {
+    p = new Proxy(obj, {});
+  },
+  run() {
+    for(var i = 0; i < ITERATIONS; i++) {
+      value = p.prop;
+    }
+  },
+  teardown() {
+    return value === SOME_NUMBER;
+  }
+});
+
+// ----------------------------------------------------------------------------
+
+newBenchmark("GetPropertyOfProxyWithTrap", {
+  setup() {
+    p = new Proxy(obj, {
+      get: function(target, propertyKey, receiver) {
+        return SOME_OTHER_NUMBER;
+      }
+    });
+  },
+  run() {
+    for(var i = 0; i < ITERATIONS; i++) {
+      value = p.prop;
+    }
+  },
+  teardown() {
+    return value === SOME_OTHER_NUMBER;
+  }
+});