Revert trial commit of "CssStyleDeclaration performance work"

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 17a875b70162e4bdc40a0456ad9b4280600a9082..69817c104bcabd2b130f4373b79488a564158054 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -3359,27 +3359,12 @@ class CssRule extends Interceptor {
 
   @DomName('CSSStyleDeclaration.setProperty')
   void setProperty(String propertyName, String value, [String priority]) {
-    return _setPropertyHelper(_browserPropertyName(propertyName),
-      value, priority);
-  }
-
-  String _browserPropertyName(String propertyName) {
-    String name = _readCache(propertyName);
-    if (name is String) return name;
     if (_supportsProperty(_camelCase(propertyName))) {
-      name = propertyName;
+      return _setPropertyHelper(propertyName, value, priority);
     } else {
-      name = Device.cssPrefix + propertyName;
+      return _setPropertyHelper(Device.cssPrefix + propertyName, value,
+          priority);
     }
-    _writeCache(propertyName, name);
-    return name;
-  }
-
-  static final _propertyCache = JS('', '{}');
-  static String _readCache(String key) =>
-    JS('String|Null', '#[#]', _propertyCache, key);
-  static void _writeCache(String key, String value) {
-    JS('void', '#[#] = #', _propertyCache, key, value);
   }
 
   static String _camelCase(String hyphenated) {
@@ -3391,9 +3376,18 @@ class CssRule extends Interceptor {
   }
 
   void _setPropertyHelper(String propertyName, String value, [String priority]) {
-    if (value == null) value = '';
-    if (priority == null) priority = '';
-    JS('void', '#.setProperty(#, #, #)', this, propertyName, value, priority);
+    // try/catch for IE9 which throws on unsupported values.
+    try {
+      if (value == null) value = '';
+      if (priority == null) {
+        priority = '';
+      }
+      JS('void', '#.setProperty(#, #, #)', this, propertyName, value, priority);
+      // Bug #2772, IE9 requires a poke to actually apply the value.
+      if (JS('bool', '!!#.setAttribute', this)) {
+        JS('void', '#.setAttribute(#, #)', this, propertyName, value);
+      }
+    } catch (e) {}
   }
 
   /**