Adding ease-of-use methods to HttpRequest.

tests/html/xhr_test.dart

Index: tests/html/xhr_test.dart
diff --git a/tests/html/xhr_test.dart b/tests/html/xhr_test.dart
index 10df44a6fa83212b901f126764c982e02505514d..3a71d7df508e7cd37deb3c982fff76c51f298f2b 100644
--- a/tests/html/xhr_test.dart
+++ b/tests/html/xhr_test.dart
@@ -8,6 +8,12 @@ import '../../pkg/unittest/lib/html_individual_config.dart';
 import 'dart:html';
 import 'dart:json' as json;
 
+void fail(message) {
+  guardAsync(() {
+    expect(false, isTrue, reason: message);
+  });
+}
+
 main() {
   useHtmlIndividualConfiguration();
   var url = "/tests/html/xhr_cross_origin_data.txt";
@@ -87,6 +93,30 @@ main() {
       }));
     });
 
+    test('XHR.getString file', () {
+      HttpRequest.getString(url).then(expectAsync1((str) {}));
+    });
+
+    test('XHR.getString No file', () {
+      HttpRequest.getString('NonExistingFile').then(
+        (_) { fail('Succeeded for non-existing file.'); },
+        onError: expectAsync1((e) {
+          validate404(e.error.target);
+        }));
+    });
+
+    test('XHR.request', () {
+      if (ArrayBuffer.supported) {
+        HttpRequest.request(url, responseType: 'ArrayBuffer').then(
+          expectAsync1((xhr) {
+            validate200Response(xhr);
+            var arrayBuffer = xhr.response;
+            expect(arrayBuffer, new isInstanceOf<ArrayBuffer>());
+            expect(arrayBuffer, isNotNull);
+          }));
+      }
+    });
+
     test('HttpRequestProgressEvent', () {
       var expectation = HttpRequestProgressEvent.supported ?
           returnsNormally : throws;