update shutdown_notebook

now that get_output_cell raises if there is no such output

IPython/html/tests/casperjs/test_cases/shutdown_notebook.js

@@ -1,47 +1,49 b''
 //
 // Test shutdown of a kernel.
 //
 casper.notebook_test(function () {
     // XXX: test.begin allows named sections but requires casperjs 1.1.0-DEV.
     //      We will put it back into place when the next version of casper is
     //      released. Following that, all instances of this.test can be changed
     //      to just test.
     //this.test.begin("shutdown tests (notebook)", 2, function(test) {
 
     // Our shutdown test closes the browser window, which will delete the
     // casper browser object, and the rest of the test suite will fail with
     // errors that look like:
     //
     //   "Error: cannot access member `evaluate' of deleted QObject"
     //
     // So what we do here is make a quick popup window, and run the test inside
     // of it.
     this.then(function() {
         this.evaluate(function(url){
             window.open(url);
         }, {url : this.getCurrentUrl()});
     })
 
     this.waitForPopup('');
     this.withPopup('', function () {
         this.thenEvaluate(function () {
             $('#kill_and_exit').click();
         });
 
         this.thenEvaluate(function () {
             var cell = IPython.notebook.get_cell(0);
             cell.set_text('a=10; print(a)');
             cell.execute();
         });
 
         this.then(function () {
-            var result = this.get_output_cell(0);
-            this.test.assertFalsy(result, "after shutdown: no execution results");
+            var outputs = this.evaluate(function() {
+                return IPython.notebook.get_cell(0).output_area.outputs;
+            })
+            this.test.assertEquals(outputs.length, 0, "after shutdown: no execution results");
             this.test.assertNot(this.kernel_running(),
                 'after shutdown: IPython.notebook.kernel.running is false ');
         });
     });
 
 //}); // end of test.begin
 });