[LayoutReloaded] Remove left/right width/height setters from Layout.Box

[LayoutReloaded] Remove left/right width/height setters from Layout.Box
https://bugs.webkit.org/show_bug.cgi?id=183731

Reviewed by Antti Koivisto.

...and use Display.Box instead.

* LayoutReloaded/FormattingContext/BlockFormatting/BlockFormattingContext.js:
(BlockFormattingContext.prototype._computeStaticPosition):
(BlockFormattingContext.prototype._computeOutOfFlowWidth):
(BlockFormattingContext.prototype._computeFloatingWidth):
(BlockFormattingContext.prototype._computeInFlowWidth):
(BlockFormattingContext.prototype._computeOutOfFlowHeight):
(BlockFormattingContext.prototype._computeFloatingHeight):
(BlockFormattingContext.prototype._computeInFlowHeight):
(BlockFormattingContext.prototype._computeInFlowPositionedPosition):
(BlockFormattingContext.prototype._computeOutOfFlowPosition):
* LayoutReloaded/FormattingContext/FloatingContext.js:
(FloatingContext.prototype.computePosition):
* LayoutReloaded/FormattingContext/FormattingContext.js:
(FormattingContext.prototype._toDisplayBox):
(FormattingContext.prototype._toLayoutBox):
* LayoutReloaded/Layout.js:
(layout):
* LayoutReloaded/LayoutTree/Box.js:
(Layout.Box.prototype.setTopLeft): Deleted.
(Layout.Box.prototype.setSize): Deleted.
(Layout.Box.prototype.setWidth): Deleted.
(Layout.Box.prototype.setHeight): Deleted.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@229702 268f45cc-cd09-0410-ab3c-d52691b4dbfc