[LayoutReloaded] Decouple formatting state and context lifetime.

[LayoutReloaded] Decouple formatting state and context lifetime.
https://bugs.webkit.org/show_bug.cgi?id=184136

Reviewed by Antti Koivisto.

FormattingContext is about the layout logic. We don't need to hold on to it.

* LayoutReloaded/FormattingContext/FloatingContext.js:
(FloatingContext):
(FloatingContext.prototype.computePosition):
(FloatingContext.prototype._positionForClear):
(FloatingContext.prototype._computePositionToAvoidIntrudingFloats):
(FloatingContext.prototype._addFloatingBox):
(FloatingContext.prototype._formattingContext):
(FloatingContext.prototype._formattingState):
* LayoutReloaded/FormattingContext/FormattingContext.js:
(FormattingContext):
* LayoutReloaded/FormattingState/BlockFormattingState.js:
(BlockFormattingState):
* LayoutReloaded/FormattingState/FloatingState.js:
(FloatingState):
(FloatingState.prototype.addFloating):
(FloatingState.prototype.formattingState):
(FloatingState.prototype.formattingContext): Deleted.
* LayoutReloaded/FormattingState/FormattingState.js:
(FormattingState):
(FormattingState.prototype.formattingContext): Deleted.
* LayoutReloaded/FormattingState/InlineFormattingState.js:
(InlineFormattingState):
* LayoutReloaded/LayoutState.js:
(LayoutState.prototype.layout):
(LayoutState.prototype.formattingContext):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@230075 268f45cc-cd09-0410-ab3c-d52691b4dbfc