Indexeddb support in Safari 10.1+

[dennismartensson]

Safari 10.1 has shipped with full and performant support for IndexedDB according to this PR over at pouchdb.

I think we should get this to localForage.

[tofumatt]

Agreed, sounds good 👍🏻

[dennismartensson]

@tofumatt do you think its a big job? I did have a quick look at it and got to that utils/isIndexedDBValid.js#L19 is where we need to change the check so that if its Safari 10.1+ its not captured by that if.

[dennismartensson]

Thinking that this changes are the same as the ones we should do to utils/isIndexedDBValid.js#L19

[thgreasi]

I can merge nolanlawson's changes to localforage, it shouldn't be a big deal. My only concern is that I won't be able to do any testing since I currently don't have any iOS device available.

--

*Thodoris Greasidis*

[tofumatt]

I can test them, but if it's working for PouchDB I think it should work for us.

[dennismartensson]

Have a PR here #651

[thgreasi]

Resolved by #651

[Narcwis]

I tested this jsfiddle on Safari 10.2 as commented on #604. The main page uses localstorage but when I open the result frame in a new tab it uses asyncstorage. Feel free to create codepen or jsfiddle for me test, I will be more than happy to contribute.

[thgreasi]

@Narcwis asyncstorage stands for IndexedDB, so your results are indicate that #651 works and this is resolved.
It seems that the safari + iframe => localstorage issue is not something we can do something for.
Thanks for your feedback confirming that this works!