Add @override annotation to known overriden methods

sky/sdk/lib/painting/text_style.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'dart:sky';
 
 enum FontWeight { w100, w200, w300, w400, w500, w600, w700, w800, w900 }
 const normal = FontWeight.w400;
 const bold = FontWeight.w700;
 
@@ skipping 134 matching lines @@
     }
     if (decoration != null) {
       cssStyle['text-decoration'] = _decorationToCSSString(decoration);
       if (decorationColor != null)
         cssStyle['text-decoration-color'] = _colorToCSSString(decorationColor);
       if (decorationStyle != null)
         cssStyle['text-decoration-style'] = _decorationStyleToCSSString(decorationStyle);
     }
   }
 
+  @override
   bool operator ==(other) {
     if (identical(this, other))
       return true;
     return other is TextStyle &&
       color == other.color &&
-      fontFamily == other.fontFamily && 
+      fontFamily == other.fontFamily &&
       fontSize == other.fontSize &&
       fontWeight == other.fontWeight &&
-      textAlign == other.textAlign && 
+      textAlign == other.textAlign &&
       decoration == other.decoration &&
       decorationColor == other.decorationColor &&
       decorationStyle == other.decorationStyle;
   }
 
+  @override
   int get hashCode {
     // Use Quiver: https://github.com/domokit/mojo/issues/236
     int value = 373;
     value = 37 * value + color.hashCode;
     value = 37 * value + fontFamily.hashCode;
     value = 37 * value + fontSize.hashCode;
     value = 37 * value + fontWeight.hashCode;
     value = 37 * value + textAlign.hashCode;
     value = 37 * value + decoration.hashCode;
     value = 37 * value + decorationColor.hashCode;
     value = 37 * value + decorationStyle.hashCode;
     return value;
   }
 
+  @override
   String toString([String prefix = '']) {
     List<String> result = [];
     if (color != null)
       result.add('${prefix}color: $color');
     // TODO(hansmuller): escape the fontFamily string.
     if (fontFamily != null)
       result.add('${prefix}fontFamily: "${fontFamily}"');
     if (fontSize != null)
       result.add('${prefix}fontSize: $fontSize');
     if (fontWeight != null)
       result.add('${prefix}fontWeight: $fontWeight');
     if (textAlign != null)
       result.add('${prefix}textAlign: $textAlign');
     if (decoration != null)
       result.add('${prefix}decoration: $decoration');
     if (decorationColor != null)
       result.add('${prefix}decorationColor: $decorationColor');
     if (decorationStyle != null)
       result.add('${prefix}decorationStyle: $decorationStyle');
     if (result.isEmpty)
       return '${prefix}<no style specified>';
     return result.join('\n');
   }
 }