Adding support for cross-origin requests on IE9.

sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index 7dd1e5fa262f46a7b84bfdc605e44c7478ccd7aa..c5aef22eacb474aea8fa677e67b1a6bc6184adbf 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -13599,6 +13599,22 @@ class HttpRequest extends EventTarget {
     return true;
   }
 
+  /**
+   * Makes a cross-origin request to the specified URL.
+   *
+   * This API provides a subset of [request] which works on IE9. If IE9
+   * cross-origin support is not required then [request] should be used instead.
+   */
+  @Experimental()
+  static Future<String> requestCrossOrigin(String url,
+      {String method, String sendData}) {
+    if (supportsCrossOrigin) {
+      return request(url, method: method, sendData: sendData).then((xhr) {
+        return xhr.responseText;
+      });
+    }
+  }
+
   // To suppress missing implicit constructor warnings.
   factory HttpRequest._() { throw new UnsupportedError("Not supported"); }