Reflect recent spec changes to V8 Extra ReadableStream impl

third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/cancel.js

 'use strict';
 
 if (self.importScripts) {
   self.importScripts('../resources/test-utils.js');
   self.importScripts('../resources/rs-utils.js');
   self.importScripts('/resources/testharness.js');
 }
 
 promise_test(() => {
 
   const randomSource = new RandomPushSource();
 
   let cancellationFinished = false;
   const rs = new ReadableStream({
     start(c) {
       randomSource.ondata = c.enqueue.bind(c);
       randomSource.onend = c.close.bind(c);
       randomSource.onerror = c.error.bind(c);
     },
 
     pull() {
       randomSource.readStart();
     },
 
     cancel() {
       randomSource.readStop();
-      randomSource.onend();
 
       return new Promise(resolve => {
         setTimeout(() => {
           cancellationFinished = true;
           resolve();
         }, 1);
       });
     }
   });
 
   const reader = rs.getReader();
 
   // We call delay multiple times to avoid cancelling too early for the
   // source to enqueue at least one chunk.
-  const cancel = delay(5).then(() => delay(5)).then(() => delay(5)).then(() => reader.cancel());
+  const cancel = delay(5).then(() => delay(5)).then(() => delay(5)).then(() => {
+    let cancelPromise = reader.cancel();
+    assert_false(cancellationFinished, 'cancellation in source should happen later');
+    return cancelPromise;
+  })
 
   return readableStreamToArray(rs, reader).then(chunks => {
     assert_greater_than(chunks.length, 0, 'at least one chunk should be read');
     for (let i = 0; i < chunks.length; i++) {
       assert_equals(chunks[i].length, 128, 'chunk ' + i + ' should have 128 bytes');
     }
-    assert_false(cancellationFinished, 'it did not wait for the cancellation process to finish before closing');
     return cancel;
   }).then(() => {
     assert_true(cancellationFinished, 'it returns a promise that is fulfilled when the cancellation finishes');
   });
 
 }, 'ReadableStream cancellation: integration test on an infinite stream derived from a random push source');
 
 test(() => {
 
   let recordedReason;
@@ skipping 170 matching lines @@
     pull() {
       assert_unreached('pull should not have been called');
     }
   });
 
   return Promise.all([rs.cancel(), rs.getReader().closed]);
 
 }, 'ReadableStream cancellation: cancelling before start finishes should prevent pull() from being called');
 
 done();