Remove some dead code from bindings/ folder

Remove some dead code from bindings/ folder. Several functions were defined but
never used.

R=haraken@chromium.org

Review URL: https://codereview.chromium.org/241513002

git-svn-id: svn://svn.chromium.org/blink/trunk@171902 bbb929c8-8fbe-4397-9dbb-9b2b20218538