Remove ScopedPersistent::deprecatedHandle.

For this, we need to also remove ScopedPersistent::is(Null|Undefined).

See https://codereview.chromium.org/19772002/ for a similar change.

The functions were used (indirectly) by IDBObjectStore::put,
IDBCursor::continueFunction, InjectedScriptHost and core/inspector; none of
these should be so performance critical that we couldn't afford to create one
extra local handle.

BUG=236290
R=haraken@chromium.org, yurys@chromium.org

Review URL: https://codereview.chromium.org/19844005

git-svn-id: svn://svn.chromium.org/blink/trunk@154647 bbb929c8-8fbe-4397-9dbb-9b2b20218538