Initial checkin of a perf test suite for Indexed Database. This just has a

chrome/test/data/indexeddb/perf_test.js

Index: chrome/test/data/indexeddb/perf_test.js
diff --git a/chrome/test/data/indexeddb/perf_test.js b/chrome/test/data/indexeddb/perf_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..4fbcfecd5d68cd2118c5e2e17bd8dd4643789763
--- /dev/null
+++ b/chrome/test/data/indexeddb/perf_test.js
@@ -0,0 +1,72 @@
+var overallTestStartTime = Date.now();
+
+function testCreateKeysInStores(
+    numKeys, numStores, payloadLength, onTestComplete) {
+  var testName = "testCreateKeysInStores_" + numKeys + "_" + numStores + "_" +
+      payloadLength;
+  assert(numKeys >= 0);
+  assert(numStores >= 1);
+  var objectStoreNames = [];
+  for (var i=0; i < numStores; ++i) {
+    objectStoreNames.push("store " + i);
+  }
+  var value = stringOfLength(payloadLength);
+  var start;
+
+  function onCreated(db) {
+    automation.setStatus("Constructing transaction.");
+    start = Date.now(); // Ignore the setup time for this test.
+    var transaction = getTransaction(db, objectStoreNames, "readwrite",
+        function() { onTransactionComplete(db); });
+    for (var i in objectStoreNames) {
+      var os = transaction.objectStore(objectStoreNames[i]);
+      assert(os);
+      for (var j = 0; j < numKeys; ++j) {
+        os.put("key " + j, value);

[jsbell, 2012/06/21 00:04:16]

This is measuring three distinct things:
* Time taken for the requests to be made (i.e. synchronous put calls)
* Time taken for the asynchronous requests to be processed
* Time for the commit to occur after the last request is processed (which could
be measured by the time delta between the last request.onsuccess and the
transaction.oncomplete)

We'll want to break those out eventually. (Many tests may interleave the first
two, but I suspect it will be common to have tests which are effectively three
different phases.)

+      }
+    }
+  }
+  function onTransactionComplete(db) {
+    var duration = Date.now() - start;
+    // Ignore the cleanup time for this test.
+    automation.addResult(testName, duration);
+    automation.setStatus("Deleting.");
+    deleteDatabase(db, onDeleted);
+  }
+  function onDeleted() {
+    automation.setStatus("Deleted.");
+    onTestComplete();
+  }
+  automation.setStatus("Creating.");
+  createDatabase(testName, objectStoreNames, onCreated, onError);
+}
+
+var tests = [
+  [testCreateKeysInStores, 1,    1,    1],
+  [testCreateKeysInStores, 100,  1,    1],
+  [testCreateKeysInStores, 1,    100,  1],
+  [testCreateKeysInStores, 100,  1,    100000]
+];
+
+var currentTest = 0;
+
+function runNextTest() {
+  if (currentTest < tests.length) {
+    var test = tests[currentTest++].slice();
+    var f = test.shift();
+    test.push(runNextTest);
+    f.apply(null, test);
+  } else {
+    onAllTestsComplete();
+  }
+}
+
+function onAllTestsComplete() {
+  var overallDuration = Date.now() - overallTestStartTime;
+  automation.addResult("OverallTestDuration", overallDuration);
+  automation.setDone();
+}
+
+function test() {
+  runNextTest();
+}