Examples: move markAsLaidOut() to just before the return, so the asserts work

sky/examples/style/hex-layout.sky

 #!mojo mojo:sky
 <import src="sky:core" as="sky"/>
 <script>
  class BeehiveLayoutManager extends sky.LayoutManager {
    function layout(width, height) {
-     this.markAsLaidOut();
      if (width == null)
        width = this.getIntrinsicWidth().value;
      let autoHeight = false;
      if (height == null) {
        height = 0;
        autoHeight = true;
      }
      this.assumeDimensions(width, height);
      let cellCount = this.node.getProperty('beehive-count');
      let cellDim = width / cellCount;
      let children = this.walkChildren();
      let loop = children.next();
      let x = 0;
      let y = 0;
      while (!loop.done) {
        let child = loop.value;
-       if (child.needsLayout || child.descendantNeedsLayout) {
+       if (child.needsLayout) {
          child.layoutManager.layout(cellDim, cellDim);
          // we ignore the size the child reported from layout(), and force it to the cell dimensions
          this.setChildSize(child, cellDim, cellDim);
+       } else if (child.descendantNeedsLayout) {
+         child.layoutManager.layoutDescendants();
+         this.setChildSize(child, cellDim, cellDim);
        }
        this.setChildPosition(child, x * cellDim + (y % 2) * cellDim/2, y * 3/4 * cellDim);
        x += 1;
        if (x > cellCount) {
          y += 1;
          x = 0;
        }
        loop = children.next();
      }
      if (height == 0)
        height = (1 + y * 3/4) * cellDim;
+     this.markAsLaidOut();
      return {
        width: width,
        height: height,
      }
    }
    function getIntrinsicHeight() {
      let height = this.node.getProperty('height');
      if (typeof height != 'number') {
        // e.g. height: auto
        width = this.getIntrinsicWidth().value;
@@ skipping 92 matching lines @@
  div { display: beehive; beehive-count: 3; }
 </style>
 <div>
  <t>Hello</t>
  <t>World</t>
  <t>How</t>
  <t>Are</t>
  <t>You</t>
  <t>Today?</t>
 </div>