js garbage collection and hide playback

[zang]

On Chrome, xhr stalls once file size reaches 500mb; create a restore function to release variables and therefore able to process further re-takes

[thijstriemstra]

@zang thanks for the PR. As you can see the build is failing, you need to use parenthese etc. Make sure to run grunt locally before pushing the changes.

Is it possible to call this restore method as soon as it's trying to stall, or as soon as you stop recording? I'm not sure a standalone method like this is useful as it is now.

[zang]

Sorry and I will sort out the checks :)

I had a strange issue recently and the recorded files stopped uploading after a few retakes. I use this function to clear the cached blobs and problem solved. I tried to add it to destroy() but the logic doesn't fit. I can't add it to finish recording as it will destroy the playback. So, I call this function after files being uploaded.

[zang]

different browsers seem to have different file size limit before it stalls, and I can't find clear definition, that's why I didn't figure out how to add it to stall-detection. :)

[thijstriemstra]

I had a strange issue recently and the recorded files stopped uploading after a few retakes.

We basically need to clear the previous blob when starting to record a new blob.

[thijstriemstra]

chrome://blob-internals/ is a useful page in the Chrome browser to monitor the creation of blobs. I managed to get it down to 1 and will push a fix soon.

[thijstriemstra]

@zang I've added a dispose method to engine and made sure all blobs are cleaned up afaik. Could you give this a try? The change you made related to resetting the playToggle, this looks similar to the request in #73 so I'll add a reset method there.