Adding IE support to browser prefixes.

lib/html/dart2js/html_dart2js.dart

Index: lib/html/dart2js/html_dart2js.dart
diff --git a/lib/html/dart2js/html_dart2js.dart b/lib/html/dart2js/html_dart2js.dart
index b5f3864e29a456a43eabccd93c282b8133fd4f3b..b623803da1d8c5ae1feae7df6cafc04e1f8ce440 100644
--- a/lib/html/dart2js/html_dart2js.dart
+++ b/lib/html/dart2js/html_dart2js.dart
@@ -917,10 +917,13 @@ String get _browserPrefix() {
   if (_cachedBrowserPrefix === null) {
     if (_Device.isFirefox) {
       _cachedBrowserPrefix = '-moz-';
+    } else if (_Device.isIE) {
+      _cachedBrowserPrefix = '-ms-';
+    } else if (_Device.isOpera) {
+      _cachedBrowserPrefix = '-o-';
     } else {
       _cachedBrowserPrefix = '-webkit-';
     }
-    // TODO(jacobr): support IE 9.0 and Opera as well.
   }
   return _cachedBrowserPrefix;
 }
@@ -39430,6 +39433,16 @@ class _Device {
   static String get userAgent() => window.navigator.userAgent;
 
   /**
+   * Determines if the current device is running Opera.
+   */
+  static bool get isOpera() => userAgent.contains("Opera", 0);
+
+  /**
+   * Determines if the current device is running Internet Explorer.
+   */
+  static bool get isIE() => !isOpera && userAgent.contains("MSIE", 0);
+
+  /**
    * Determines if the current device is running Firefox.
    */
   static bool get isFirefox() => userAgent.contains("Firefox", 0);