Add use counter for document.all.tags

Also move tags from HTMLCollection.{h,cpp} to HTMLAllCollection.{h,cpp}
since it is only used by HTMLAllCollection.idl.

BUG=290891

Review URL: https://chromiumcodereview.appspot.com/23444059

git-svn-id: svn://svn.chromium.org/blink/trunk@157761 bbb929c8-8fbe-4397-9dbb-9b2b20218538