Revert of ResizeObserver pt6: integration (patchset #8 id:140001 of https://codereview.chromium.org/2204503002/ )

Reason for revert:
Causing layout test failure:
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Leak/builds/21873

Original issue's description:
> ResizeObserver pt6: integration
>
> Integrates ResizeObserver with the browser.
>
> 1) Element notifies ResizeObserver when its size might have changed.
>
> Operations that might change Element's observed size are trapped:
> Element::detachLayoutTree traps Element removal from DOM tree
> LayoutObject::setMayNeedPaintInvalidation traps size changes
>
> 2) Event loop integration
>
> FrameView::notifyResizeObserver implements it per spec.
> https://wicg.github.io/ResizeObserver/#html-event-loop
>
> 3) Tests
>
> LayoutTests/resize-observer is a comprehensive test suite.
>
> BUG=612962
>
> Committed: https://crrev.com/5b49641e336ba9be7789cc0eb2511d415f4e6d5d
> Cr-Commit-Position: refs/heads/master@{#411694}

TBR=esprehn@chromium.org,eae@chromium.org,atotic@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=612962

Review-Url: https://codereview.chromium.org/2242773003
Cr-Commit-Position: refs/heads/master@{#411725}
18 files changed