Merge pull request #296 from Unity-Technologies/zxw/fix_material_text_direction

fix material issue

com.unity.uiwidgets/Runtime/material/material.cs

                     shape: shape,
                     borderOnForeground: widget.borderOnForeground),
                 clipper: new ShapeBorderClipper(
-                    shape: shape),
+                    shape: shape,
+                    textDirection: Directionality.of(context)),
                 clipBehavior: widget.clipBehavior,
                 elevation: _elevation.evaluate(animation),
                 color: ElevationOverlay.applyOverlay(context, widget.color, elevation),

com.unity.uiwidgets/Runtime/material/popup_menu.cs

             ValueChanged<Size> onLayout = null,
             Widget child = null
         ) : base(key: key, child: child) {
-            Debug.Log(onLayout != null);
             this.onLayout = onLayout;
         }