Indent automatically when using electric-pair-mode

[Radon Rosborough]

In js2-mode, with electric-pair-mode enabled, and point | positioned as follows:

{|}

I can press RET to get the following:

{
    |
}

Unfortunately, doing the same in json-mode only gives:

{
|}

I think this may have something to do with the syntax table (not) provided by json-mode, since both js2-mode and json-mode inherit from js-mode.

[taku0]

It works now.