[ServiceWorker] CacheStorage tests.

LayoutTests/http/tests/serviceworker/resources/worker-test-harness.js

 /*
  * worker-test-harness should be considered a temporary polyfill around
  * testharness.js for supporting Service Worker based tests. It should not be
  * necessary once the test harness is able to drive worker based tests natively.
  * See https://github.com/w3c/testharness.js/pull/82 for status of effort to
  * update upstream testharness.js. Once the upstreaming is complete, tests that
  * reference worker-test-harness should be updated to directly import
  * testharness.js.
  */
 
@@ skipping 66 matching lines @@
 // boilerplate for testing with promises.
 function promise_test(func, name, properties) {
   properties = properties || {};
   var test = async_test(name, properties);
   Promise.resolve(test.step(func, test, test))
     .then(function() { test.done(); })
     .catch(test.step_func(function(value) {
         throw value;
       }));
 }
+
+// Returns a promise that fulfills after the provided |promise| is fulfilled.
+// The |test| succeeds only if |promise| throws an exception matching |code|.
+// The optional |description| describes the test being performed.
+// E.g.:
+//   assert_promise_throws(
+//       new Promise(...), // something that should throw an exception.
+//       'NotFoundError',
+//       'Should throw NotFoundError.');
+function assert_promise_throws(promise, code, description) {
+  return promise.then(
+    function() {
+      throw 'assert_promise_throws: ' + description + ' Promise did now throw.';

[jsbell, 2014/08/27 22:28:23]

Typo: now -> not

[asanka, 2014/08/28 00:02:56]

Done.

+    },
+    function(e) {
+      if (code in self) {
+        // If |code| is a JavaScript error exposed in the global object, then
+        // require that the thrown exception be of that type.
+        assert_class_string(e, code, description);

[jsbell, 2014/08/27 21:56:47]

This doesn't work - the Error subclasses like TypeError don't define a unique
[[Class]] (ES5) / @@toStringTag (ES6):

Object.prototype.toString.call(new TypeError); // "[object Error]"

[asanka, 2014/08/28 00:02:56]

Ah. Hack removed. We are now calling assert_promise_throws() with a 'new
TypeError()' instead.

+      } else {
+        assert_throws(code, function() { throw e; }, description);
+      }
+    });
+}