Move runin to original position when sibling element is destroyed. Additionally, if If moveRunInUnderSiblingBlockIfNeeded is called when the sibling run-in block is being destroyed, it means that the run-in is moving to original position and we do not need to do nothing.

R=
BUG=260388

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=154557

Review URL: https://chromiumcodereview.appspot.com/19290002

git-svn-id: svn://svn.chromium.org/blink/trunk@154884 bbb929c8-8fbe-4397-9dbb-9b2b20218538