debug error fix2

Runtime/material/tabs.cs

         
         public override bool applyContentDimensions(float minScrollExtent, float maxScrollExtent) {
             bool result = true;
-            if (this._pixels == null) {
+            if (!this.havePixels) {
                 this.correctPixels(this.tabBar._initialScrollOffset(this.viewportDimension, minScrollExtent, maxScrollExtent));
                 result = false;
             }
                 position.maxScrollExtent);
         }
 
-        public float _initialScrollOffset(float viewportWidth, float minExtent, float maxExtent) {
+        internal float _initialScrollOffset(float viewportWidth, float minExtent, float maxExtent) {
             return this._tabScrollOffset(this._currentIndex, viewportWidth, minExtent, maxExtent);
         }
 

Runtime/widgets/scroll_position.cs

             }
         }
 
-        public bool hasPixles {
+        public bool havePixels {
             get { return this._pixels != null; }
         }