Rename ReadableStream.wait() to ReadableStream.ready.

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

 var global = this;
 if (global.importScripts) {
     // Worker case
     importScripts('/resources/testharness.js');
 }
 
 var testInLoadingState = async_test('Test aborting XMLHttpRequest with responseType set to "stream" in LOADING state.');
 
 testInLoadingState.step(function()
 {
@@ skipping 41 matching lines @@
         }
     });
 
     xhr.open('GET', '/resources/test.ogv', true);
     xhr.send();
 });
 
 var testInDoneState = async_test('Test aborting XMLHttpRequest with responseType set to "stream" in DONE state.');
 
 function readUntilDone(stream) {
-    return stream.wait().then(function() {
+    return stream.ready.then(function() {
         while (stream.state == 'readable') {
             stream.read();
         }
         if (stream.state == 'closed' || stream.state == 'errored') {
             return stream.closed;
         } else {
             return readUntilDone(stream);
         }
     });
 }
@@ skipping 51 matching lines @@
     });
 
     xhr.open('GET', '/resources/test.ogv', true);
     xhr.send();
 });
 
 if (global.importScripts) {
     // Worker case
     done();
 }