Update unittest to new package layout.

pkg/unittest/coverage_controller.js

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/**
- * Coverage controller logic - used by coverage test harness to embed tests in
- * DumpRenderTree and extract coverage information.
- */
-
-var LONG_LINE = 60000;
-
-function onReceive(e) {
-  if (e.data == 'unittest-suite-done') {
-    var s = JSON.stringify(top._$jscoverage);
-    var res = '';
-    // DumpRenderTree has a bug on lines longer than 2^16, so we split them
-    while (s.length > LONG_LINE) {
-      res += s.substr(0, LONG_LINE) + '<br>\n';
-      s = s.substr(LONG_LINE);
-    }
-    res += s;
-    window.document.body.innerHTML = res;
-    window.layoutTestController.notifyDone();
-  }
-}
-
-if (window.layoutTestController) {
-  window.layoutTestController.dumpAsText();
-  window.layoutTestController.waitUntilDone();
-  window.addEventListener("message", onReceive, false);
-}