Updated charted DEP to 0.4.X

packages/charted/lib/charts/cartesian_renderers/cartesian_base_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 164 matching lines @@
         _columnStateCache[column] = flags;
       });
     });
   }
 
   Iterable<String> stylesForColumn(int column) {
     if (_columnStylesCache[column] == null) {
       if (state == null || area.useRowColoring) {
         _columnStylesCache[column] = const [];
       } else {
-        var styles = [], flags = _columnStateCache[column];
+        var styles = <String>[], flags = _columnStateCache[column];
 
         if (flags & ChartState.COL_SELECTED != 0) {
           styles.add(ChartState.COL_SELECTED_CLASS);
         } else if (flags & ChartState.COL_UNSELECTED != 0) {
           styles.add(ChartState.COL_UNSELECTED_CLASS);
         }
 
         if (flags & ChartState.COL_HIGHLIGHTED != 0) {
           styles.add(ChartState.COL_HIGHLIGHTED_CLASS);
         } else if (flags & ChartState.COL_UNHIGHLIGHTED != 0) {
@@ skipping 73 matching lines @@
       }
       if (state.hovered != null && state.hovered.last == row) {
         flags |= ChartState.VAL_HOVERED;
       }
       _valueColorCache[hash] =
           theme.getColorForKey(area.useRowColoring ? row : column, flags);
       _valueFilterCache[hash] = theme.getFilterForState(flags);
     }
   }
 }