Add browser_tests for FileAPI with Quota.

chrome/test/data/fileapi/common.js

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+function debug(message)
+{
+  document.getElementById('status').innerHTML += '<br/>' + message;
+}
+
+function done(message)
+{
+  if (document.location.hash == '#fail')
+    return;
+  if (message)
+    debug('PASS: ' + message);
+  else
+    debug('PASS');
+  document.location.hash = '#pass';
+}
+
+function fail(message)
+{
+  debug('FAILED: ' + message);
+  document.location.hash = '#fail';
+}
+
+function getLog()
+{
+  return "" + document.getElementById('status').innerHTML;

[kinuko, 2011/08/30 12:12:04]

"" -> '' for consistency?

is this '"" +' placed to make sure we get a string?

+}
+
+function fileErrorToString(e) {
+  switch (e.code) {
+    case FileError.QUOTA_EXCEEDED_ERR:
+      msg = 'QUOTA_EXCEEDED_ERR';

[kinuko, 2011/08/30 12:12:04]

looks like we can simply do this?

return 'QUOTA_EXCEEDED_ERR';

otherwise I think we should declare 'var msg' at the top of this method.

+      break;
+    case FileError.NOT_FOUND_ERR:
+      msg = 'NOT_FOUND_ERR';
+      break;
+    case FileError.SECURITY_ERR:
+      msg = 'SECURITY_ERR';
+      break;
+    case FileError.INVALID_MODIFICATION_ERR:
+      msg = 'INVALID_MODIFICATION_ERR';
+      break;
+    case FileError.INVALID_STATE_ERR:
+      msg = 'INVALID_STATE_ERR';
+      break;
+    default:
+      msg = 'Unknown Error';
+      break;
+  };

[kinuko, 2011/08/30 12:12:04]

nit: semicolon is not needed here?

+  return msg;
+}
+
+function unexpectedErrorCallback(e)
+{
+  fail('unexpectedErrorCallback:' + fileErrorToString(e));
+}