Revert "Refactor adding and removing named and IDed elements"

This reverts commit 40bde9ee3f3600730bd3f1a8003d8eef5413620c.

This CL caused a top crash:

Stack Signature: WTF::StringHasher::addCharactersAssumingAligned<wchar_t,&WTF::StringHasher::defaultConverter(...
New Signature Label: WTF::StringHasher::addCharactersAssumingAligned<wchar_t,&WTF::StringHasher::defaultConverter(wchar_t...
New Signature Hash: 043b570f_bacaa33a_6ba2cda4_9237a890_aaa1ba4b

BUG=271237
TBR=adamk@chromium.org

Review URL: https://codereview.chromium.org/22875005

git-svn-id: svn://svn.chromium.org/blink/trunk@155942 bbb929c8-8fbe-4397-9dbb-9b2b20218538