Remove unused method and de-virtualize others in Element.h

The de-virtualization possibilities were noted whilst "FINALizing" the Node
hierarchy. If a method is successfully marked FINAL but then fails when marked
OVERRIDE as well, the method by definition does not need to be virtual.

R=esprehn@chromium.org
TEST=wktry

Review URL: https://codereview.chromium.org/14722005

git-svn-id: svn://svn.chromium.org/blink/trunk@149493 bbb929c8-8fbe-4397-9dbb-9b2b20218538
1 file changed