[LFC] Formatting contexts should create floating states.

[LFC] Formatting contexts should create floating states.
https://bugs.webkit.org/show_bug.cgi?id=185032

Reviewed by Antti Koivisto.

This patch implements the logic for sharing floating states across multiple formatting contexts.
At this point this is mostly about inline formatting contexts. They either create a new floating state
or inherit it from the parent formatting context.

* layout/FloatingState.cpp:
(WebCore::Layout::FloatingState::FloatingState):
* layout/FloatingState.h:
(WebCore::Layout::FloatingState::create):
* layout/FormattingContext.cpp:
(WebCore::Layout::FormattingContext::FormattingContext):
* layout/FormattingContext.h:
(WebCore::Layout::FormattingContext::layoutContext const):
* layout/FormattingState.cpp:
(WebCore::Layout::FormattingState::FormattingState):
* layout/FormattingState.h:
(WebCore::Layout::FormattingState::floatingState const):
* layout/LayoutContext.cpp:
(WebCore::Layout::LayoutContext::updateLayout):
(WebCore::Layout::LayoutContext::formattingStateForBox const):
(WebCore::Layout::LayoutContext::establishedFormattingState):
(WebCore::Layout::LayoutContext::formattingContext):
(WebCore::Layout::LayoutContext::formattingState): Deleted.
* layout/LayoutContext.h:
* layout/blockformatting/BlockFormattingContext.cpp:
(WebCore::Layout::BlockFormattingContext::BlockFormattingContext):
(WebCore::Layout::BlockFormattingContext::createFormattingState const):
(WebCore::Layout::BlockFormattingContext::createOrFindFloatingState const):
(WebCore::Layout::BlockFormattingContext::formattingState const): Deleted.
* layout/blockformatting/BlockFormattingContext.h:
* layout/blockformatting/BlockFormattingState.cpp:
(WebCore::Layout::BlockFormattingState::BlockFormattingState):
* layout/blockformatting/BlockFormattingState.h:
* layout/inlineformatting/InlineFormattingContext.cpp:
(WebCore::Layout::InlineFormattingContext::InlineFormattingContext):
(WebCore::Layout::InlineFormattingContext::createFormattingState const):
(WebCore::Layout::InlineFormattingContext::createOrFindFloatingState const):
(WebCore::Layout::InlineFormattingContext::formattingState const): Deleted.
* layout/inlineformatting/InlineFormattingContext.h:
* layout/inlineformatting/InlineFormattingState.cpp:
(WebCore::Layout::InlineFormattingState::InlineFormattingState):
* layout/inlineformatting/InlineFormattingState.h:
* layout/layouttree/LayoutBox.cpp:
(WebCore::Layout::Box::formattingContextRoot const):
* layout/layouttree/LayoutBox.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@231096 268f45cc-cd09-0410-ab3c-d52691b4dbfc