Streams Implementation Update: async read

LayoutTests/http/tests/xmlhttprequest/resources/response-stream.js

 var global = this;
 if (global.importScripts) {
     // Worker case
     importScripts('/resources/testharness.js');
 }
 
 var test = async_test('Test response of XMLHttpRequest with responseType set to "stream" for various readyState.');
 
 test.step(function() {
     var xhr = new XMLHttpRequest;
 
     xhr.responseType = 'stream';
     assert_equals(xhr.responseType, 'stream', 'xhr.responseType');
 
     assert_equals(xhr.readyState, xhr.UNSENT, 'xhr.readyState');
     assert_equals(xhr.response, null, 'xhr.response during UNSENT');
 
     var seenStates = [];
 
     function readStream(reader) {
         var chunks = [];
-        function rec(resolve, reject) {
-            while (reader.state === 'readable') {
-                chunks.push(reader.read());
-            }
-            if (reader.state === 'closed') {
-                resolve(chunks);
-                return;
-            }
-            reader.ready.then(function() {
-                rec(resolve, reject);
-            }).catch(reject);
+        function consume() {
+            return reader.read().then(function(result) {
+                if (result.done) {
+                    return chunks;
+                } else {
+                    chunks.push(result.value);
+                    return consume();
+                }
+            });
         }
-        return new Promise(rec);
+        return consume();
     }
     var streamPromise = undefined;
 
     xhr.onreadystatechange = test.step_func(function() {
         // onreadystatechange can be invoked multiple times in LOADING state.
         if (seenStates.length == 0 || xhr.readyState != seenStates[seenStates.length - 1])
             seenStates.push(xhr.readyState);
 
         switch (xhr.readyState) {
         case xhr.UNSENT:
@@ skipping 19 matching lines @@
                 assert_equals(xhr.status, 200, 'xhr.status');
 
                 // Check that we saw all states.
                 assert_array_equals(seenStates,
                     [xhr.OPENED, xhr.HEADERS_RECEIVED, xhr.LOADING, xhr.DONE]);
                 var size = 0;
                 for (var i = 0; i < chunks.length; ++i) {
                     size += chunks[i].byteLength;
                 }
                 assert_equals(size, 103746, 'response size');
-                return xhr.response.closed;
+                return xhr.response.getReader().closed;
             }).then(function() {
                 test.done();
             }).catch(test.step_func(function(e) {
                 throw e;
             }));
             return;
 
         case xhr.DONE:
             return;
 
         default:
             assert_unreached('Unexpected readyState: ' + xhr.readyState)
             return;
         }
     });
 
     xhr.open('GET', '/resources/test.ogv', true);
     xhr.send();
 });
 
 if (global.importScripts) {
     // Worker case
     done();
 }