Roll Observatory deps (charted -> ^0.3.0)

packages/csslib/lib/src/property.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /** Representations of CSS styles. */
 
 part of csslib.parser;
 
 // TODO(terry): Prune down this file we do need some of the code in this file
 //              for darker, lighter, how to represent a Font, etc but alot of
@@ skipping 260 matching lines @@
         case _rgbCss:
           return Color.convertToHexString(args[0], args[1], args[2]);
         case _rgbaCss:
           return Color.convertToHexString(args[0], args[1], args[2], args[3]);
         case _hslCss:
           return new Hsla(args[0], args[1], args[2]).toHexArgbString();
         case _hslaCss:
           return new Hsla(args[0], args[1], args[2], args[3]).toHexArgbString();
         default:
           // Type not defined UnsupportedOperationException should have thrown.
-          assert(true);
+          assert(false);
           break;
       }
     }
+    return null;
   }
 
   static int hexToInt(String hex) => int.parse(hex, radix: 16);
 
   static String convertToHexString(int r, int g, int b, [num a]) {
     String rHex = Color._numAs2DigitHex(Color._clamp(r, 0, 255));
     String gHex = Color._numAs2DigitHex(Color._clamp(g, 0, 255));
     String bHex = Color._numAs2DigitHex(Color._clamp(b, 0, 255));
     String aHex = (a != null)
         ? Color._numAs2DigitHex((Color._clamp(a, 0, 1) * 255).round())
@@ skipping 483 matching lines @@
   int get hashCode => toHexArgbString().hashCode;
 }
 
 /** X,Y position. */
 class PointXY implements _StyleProperty {
   final num x, y;
   const PointXY(this.x, this.y);
 
   String get cssExpression {
     // TODO(terry): TBD
+    return null;
   }
 }
 
 // TODO(terry): Implement style and color.
 /**
  * Supports border for measuring with layout.
  */
 class Border implements _StyleProperty {
   final int top, left, bottom, right;
 
@@ skipping 426 matching lines @@
   num get width => (left != null ? left : 0) + (right != null ? right : 0);
 
   /**
    * The total size of the vertical edges. Equal to [top] + [bottom], where
    * null is interpreted as 0px.
    */
   num get height => (top != null ? top : 0) + (bottom != null ? bottom : 0);
 }
 
 _mergeVal(x, y) => y != null ? y : x;