Upgrade V8 Benchmark from v4 to v6.

chrome/test/data/v8_benchmark/base.js

Index: chrome/test/data/v8_benchmark/base.js
diff --git a/chrome/test/data/v8_benchmark/base.js b/chrome/test/data/v8_benchmark/base.js
index a22920b532b42d87beebaa0ad3fef7d3e3c06be1..ffabf24ddafc91b308c328bcce3b000d3f789870 100644
--- a/chrome/test/data/v8_benchmark/base.js
+++ b/chrome/test/data/v8_benchmark/base.js
@@ -78,7 +78,7 @@ BenchmarkSuite.suites = [];
 // Scores are not comparable across versions. Bump the version if
 // you're making changes that will affect that scores, e.g. if you add
 // a new benchmark or change an existing one.
-BenchmarkSuite.version = '4';
+BenchmarkSuite.version = '6';
 
 
 // To make the benchmark results predictable, we replace Math.random
@@ -91,7 +91,6 @@ Math.random = (function() {
     seed = ((seed ^ 0xc761c23c) ^ (seed >>> 19)) & 0xffffffff;
     seed = ((seed + 0x165667b1) + (seed << 5))   & 0xffffffff;
     seed = ((seed + 0xd3a2646c) ^ (seed << 9))   & 0xffffffff;
-    seed = ((seed + 0xd3a2646c) ^ (seed << 9))   & 0xffffffff;
     seed = ((seed + 0xfd7046c5) + (seed << 3))   & 0xffffffff;
     seed = ((seed ^ 0xb55a4f09) ^ (seed >>> 16)) & 0xffffffff;
     return (seed & 0xfffffff) / 0x10000000;
@@ -199,15 +198,33 @@ BenchmarkSuite.prototype.NotifyError = function(error) {
 
 // Runs a single benchmark for at least a second and computes the
 // average time it takes to run a single iteration.
-BenchmarkSuite.prototype.RunSingleBenchmark = function(benchmark) {
-  var elapsed = 0;
-  var start = new Date();
-  for (var n = 0; elapsed < 1000; n++) {
-    benchmark.run();
-    elapsed = new Date() - start;
+BenchmarkSuite.prototype.RunSingleBenchmark = function(benchmark, data) {
+  function Measure(data) {
+    var elapsed = 0;
+    var start = new Date();
+    for (var n = 0; elapsed < 1000; n++) {
+      benchmark.run();
+      elapsed = new Date() - start;
+    }
+    if (data != null) {
+      data.runs += n;
+      data.elapsed += elapsed;
+    }
+  }
+
+  if (data == null) {
+    // Measure the benchmark once for warm up and throw the result
+    // away. Return a fresh data object.
+    Measure(null);
+    return { runs: 0, elapsed: 0 };
+  } else {
+    Measure(data);
+    // If we've run too few iterations, we continue for another second.
+    if (data.runs < 32) return data;
+    var usec = (data.elapsed * 1000) / data.runs;
+    this.NotifyStep(new BenchmarkResult(benchmark, usec));
+    return null;
   }
-  var usec = (elapsed * 1000) / n;
-  this.NotifyStep(new BenchmarkResult(benchmark, usec));
 }
 
 
@@ -221,6 +238,7 @@ BenchmarkSuite.prototype.RunStep = function(runner) {
   var length = this.benchmarks.length;
   var index = 0;
   var suite = this;
+  var data;
 
   // Run the setup, the actual benchmark, and the tear down in three
   // separate steps to allow the framework to yield between any of the
@@ -242,12 +260,13 @@ BenchmarkSuite.prototype.RunStep = function(runner) {
 
   function RunNextBenchmark() {
     try {
-      suite.RunSingleBenchmark(suite.benchmarks[index]);
+      data = suite.RunSingleBenchmark(suite.benchmarks[index], data);
     } catch (e) {
       suite.NotifyError(e);
       return null;
     }
-    return RunNextTearDown;
+    // If data is null, we're done with this benchmark.
+    return (data == null) ? RunNextTearDown : RunNextBenchmark();
   }
 
   function RunNextTearDown() {