Added shim for scrollX and scrollY for IE 9.

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 516c4162b821e180dccdff851b8033982d06c497..a95ec054e18adc246a67567baeb0efeb7a83d623 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -25807,11 +25807,11 @@ class Window extends EventTarget implements WindowBase, WindowTimers {
 
   @DomName('Window.scrollX')
   @DocsEditable()
-  int get scrollX native "Window_scrollX_Getter";
+  int get $dom_scrollX native "Window_scrollX_Getter";
 
   @DomName('Window.scrollY')
   @DocsEditable()
-  int get scrollY native "Window_scrollY_Getter";
+  int get $dom_scrollY native "Window_scrollY_Getter";
 
   @DomName('Window.scrollbars')
   @DocsEditable()
@@ -26320,6 +26320,11 @@ class Window extends EventTarget implements WindowBase, WindowTimers {
   void moveTo(Point p) {
     $dom_moveTo(p.x, p.y);
   }
+
+  int get scrollX() => Device.isIE ? document.documentElement.scrollLeft : 
+      $dom_scrollX;
+  int get scrollY() => Device.isIE ? document.documentElement.scrollTop : 
+      $dom_scrollY;
 }
 
 /**