Update charted to 0.4.8 and roll

packages/charted/lib/core/text_metrics.dart

 //
 // Copyright 2014 Google Inc. All rights reserved.
 //
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file or at
 // https://developers.google.com/open-source/licenses/bsd
 //
 
 /// Provides a way to measure rendered text width for clipping
 /// text on tooltips and ticks when they are too long.
@@ skipping 82 matching lines @@
       width = width - ellipsis;
       while (max >= min) {
         mid = (min + max) ~/ 2;
         position = indices[mid];
         if (context.measureText(text.substring(0, position)).width > width) {
           max = mid - 1;
         } else {
           min = mid + 1;
         }
       }
+      if (max < 0) max = 0;
       text = text.substring(0, indices[max]) + '…';
     }
     return text;
   }
 
   /// Truncates text in the given [element], which is either a [SvgTextElement]
   /// or a [SvgTspanElement] to fit in [width]. Appends an ellipsis to the text
   /// if it had to be truncated.
   /// Calling this method may force a layout on the document. For better
   /// performance, use [TextMetrics.ellipsizeText].
   static ellipsizeTextElement() {}
 }