[Fetch API] Streaming error should be reported as a TypeError

third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/body-mixin.js

 if (self.importScripts) {
   importScripts('../resources/fetch-test-helpers.js');
   importScripts('/streams/resources/rs-utils.js');
 }
 
 function isLocked(stream) {
   try {
     var reader = stream.getReader();
     reader.releaseLock();
     return false;
@@ skipping 277 matching lines @@
 
 promise_test(t => {
     var res = new Response('');
     const reader = res.body.getReader();
     return res.text().then(unreached_fulfillment(t), e => {
         reader.releaseLock();
         assert_equals(e.name, 'TypeError');
       });
   }, 'Locked => text');
 
+promise_test(t => {
+    return fetch('/fetch/resources/slow-failure.cgi').then(response => {
+        return response.text().then(unreached_fulfillment(t), e => {
+            assert_equals(e.name, 'TypeError');
+          });
+      });
+  }, 'streaming error');
+
 done();