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

Specs: introduce layoutDescendants() to avoid work when a layout
manager is unaffected by its childrens' intrinsic dimensions
Examples: update for layoutDescendants() change
Specs: add "lifetime" to resolver settings so that a transition can
avoid having to dirty every consumer of the property every frame when
it only needs to update the objects that are changing that frame
Specs: expose the parents on AbstractStyleDeclarationList subclasses
Specs: fix documentation around autoreap
Specs: fix definition of setProperty()
Specs: clean up the dimension-related logic of layout managers

Review URL: https://codereview.chromium.org/850593003

examples/style/block-layout.sky

@@ -7,7 +7,6 @@ SKY MODULE
 <script>
  module.exports.BlockLayoutManager = class BlockLayoutManager extends sky.LayoutManager {
    function layout(width, height) {
-     this.markAsLaidOut();
      if (width == null)
        width = this.getIntrinsicWidth().value;
      let autoHeight = false;
@@ -31,11 +30,15 @@ SKY MODULE
      }
      if (autoHeight)
        height = y;
+     this.markAsLaidOut();
      return {
        width: width,
        height: height,
      }
    }
+   function layoutDescendants() {
+     this.layout(node.width, node.height);
+   }
    function getIntrinsicWidth() {
      let width = this.node.getProperty('width');
      if (typeof width != 'number') {

examples/style/hex-layout.sky

@@ -3,7 +3,6 @@
 <script>
  class BeehiveLayoutManager extends sky.LayoutManager {
    function layout(width, height) {
-     this.markAsLaidOut();
      if (width == null)
        width = this.getIntrinsicWidth().value;
      let autoHeight = false;
@@ -20,10 +19,13 @@
      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;
@@ -35,6 +37,7 @@
      }
      if (height == 0)
        height = (1 + y * 3/4) * cellDim;
+     this.markAsLaidOut();
      return {
        width: width,
        height: height,

examples/style/toolbar-layout.sky

@@ -23,7 +23,6 @@ SKY MODULE
      this.overflowChild = null;
    }
    function layout(width, height) {
-     this.markAsLaidOut();
      let children = null;
      let loop = null;
      if (height == null)
@@ -58,7 +57,7 @@ SKY MODULE
              childHeight = childHeight.value;
            else
              childHeight = height;
-           dims = child.layoutManager.layout(width, height);
+           dims = child.layoutManager.layout(null, height);
            this.setChildSize(child, dims.width, dims.height);
          } else {
            dims = {
@@ -125,11 +124,15 @@ SKY MODULE
      else
        this.firstSkippedChild = this.overflowChild;
 
+     this.markAsLaidOut();
      return {
        width: width,
        height: height,
      }
    }
+   function layoutDescendants() {
+     this.layout(node.width, node.height);
+   }
    function getIntrinsicWidth() {
      let width = this.node.getProperty('width');
      if (typeof width != 'number') {