dom: Makes ConsoleBase inherit from ScriptWrappable.

Makes ConsoleBase, instead of its subclasses, inherit from ScriptWrappable.

BUG=235436

Review URL: https://codereview.chromium.org/396803011

git-svn-id: svn://svn.chromium.org/blink/trunk@178377 bbb929c8-8fbe-4397-9dbb-9b2b20218538