Merge pull request #96 from UnityTech/xwzhu

remove warnings

Runtime/flow/instrumentation.cs

 
     public class Stopwatch {
         float _start;
-        float[] _laps;
+        readonly float[] _laps;
-        bool _cacheDirty;
 
         public Stopwatch() {
             this._start = InstrumentationUtils.now();
             for (int i = 0; i < this._laps.Length; i++) {
                 this._laps[i] = delta;
             }
-
-            this._cacheDirty = true;
         }
 
         public void start() {

Runtime/material/app_bar.cs

                 default:
                     return false;
             }
-
-            return null;
         }
 
         public override State createState() {
 
             Widget title = this.widget.title;
             if (title != null) {
-                bool namesRoute = false;
-                switch (Application.platform) {
-                    case RuntimePlatform.IPhonePlayer:
-                        break;
-                    default:
-                        namesRoute = true;
-                        break;
-                }
-
                 title = new DefaultTextStyle(
                     style: centerStyle,
                     softWrap: false,

Runtime/material/back_button.cs

                 default:
                     return Icons.arrow_back;
             }
-
-            D.assert(false);
-            return null;
         }
 
         public override Widget build(BuildContext context) {

Runtime/material/flexible_space_bar.cs

                 default:
                     return false;
             }
-
-            return null;
         }
 
 

Runtime/material/switch.cs

             switch (this.widget.materialTapTargetSize ?? theme.materialTapTargetSize) {
                 case MaterialTapTargetSize.padded:
                     return new Size(Switch._kSwitchWidth, Switch._kSwitchHeight);
-                    break;
-                    break;
             }
             D.assert(false);
             return null;

Runtime/rendering/table.cs

                 }
             }
 
-            D.assert(!widths.Any((float value) => { return value == null; }));
             float maxWidthConstraint = constraints.maxWidth;
             float minWidthConstraint = constraints.minWidth;
 
             this._columnLefts = positions;
             tableWidth = positions.Last() + widths.Last();
 
-            D.assert(!positions.Any((float value) => { return value == null; }));
             this._rowTops.Clear();
             this._baselineDistance = null;