Update charted to 0.4.8 and roll

packages/charted/lib/charts/cartesian_renderers/stackedbar_chart_renderer.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
 //
 
 part of charted.charts;
 
@@ skipping 151 matching lines @@
         if (yPos != pos) {
           yPos += (theme.defaultSeparatorWidth + theme.defaultStrokeWidth);
         }
         return pos;
       }
     };
 
     var buildPath = (d, int i, Element e, bool animate, int roundIdx) {
       var position = animate ? getInitialBarPos(i) : getBarPos(d, i),
           length = animate ? 0 : getBarLength(d, i),
-          radius =
-          series.measures.elementAt(_reverseIdx(i)) == roundIdx ? RADIUS : 0,
+          radius = series.measures.elementAt(_reverseIdx(i)) == roundIdx
+              ? RADIUS
+              : 0,
           path = (length != 0)
               ? verticalBars
                   ? topRoundedRect(0, position, barWidth, length, radius)
                   : rightRoundedRect(position, 0, length, barWidth, radius)
               : '';
       e.attributes['data-offset'] =
           verticalBars ? position.toString() : (position + length).toString();
       return path;
     };
 
@@ skipping 70 matching lines @@
     root.selectAll('.stack-rdr-rowgroup').remove();
   }
 
   @override
   double get bandInnerPadding =>
       area.theme.getDimensionAxisTheme().axisBandInnerPadding;
 
   @override
   Extent get extent {
     assert(area != null && series != null);
-    var rows = area.data.rows,
-        max = SMALL_INT_MIN,
-        min = SMALL_INT_MAX,
-        rowIndex = 0;
+    var rows = area.data.rows, rowIndex = 0;
+    num max = SMALL_INT_MIN;
+    num min = SMALL_INT_MAX;
     _lastMeasureWithData = new List.generate(rows.length, (i) => -1);
 
     rows.forEach((row) {
-      var bar = null;
+      num bar = null;
       series.measures.forEach((idx) {
         var value = row.elementAt(idx);
         if (value != null && value.isFinite) {
           if (bar == null) bar = 0;
           bar += value;
           if (value.round() != 0 && _lastMeasureWithData[rowIndex] == -1) {
             _lastMeasureWithData[rowIndex] = idx;
           }
         }
       });
@@ skipping 41 matching lines @@
     var row = rowStr != null ? int.parse(rowStr) : null;
     controller.add(new DefaultChartEventImpl(scope.event, area, series, row,
         series.measures.elementAt(_reverseIdx(index)), data));
   }
 
   // Stacked bar chart renders items from bottom to top (first measure is at
   // the bottom of the stack). We use [_reversedIdx] instead of index to
   // match the color and order of what is displayed in the legend.
   int _reverseIdx(int index) => series.measures.length - 1 - index;
 }