TypeError when attempting to play protected media on insecure origin

[davemevans]

Environment

• The MPD passes the DASH-IF Conformance Tool on http://dashif.org/conformance.html
• The stream has correct Access-Control-Allow-Origin headers (CORS)
• There are no network errors such as 404s in the browser console when trying to play the stream
• The issue observed is not mentioned on https://github.com/Dash-Industry-Forum/dash.js/wiki/FAQ
• The issue occurs in the latest reference client on http://reference.dashif.org/dash.js/ and not just on my page

• Link to playable MPD file: any protected content, e.g: https://media.axprod.net/TestVectors/v7-MultiDRM-SingleKey/Manifest_1080p.mpd
• Dash.js version: nightly
• Browser name/version: Chrome (probably any though)
• OS name/version: Win7 (but probably any)

Steps to reproduce

1. Load player on insecure origin eg http://reference.dashif.org/dash.js/nightly/samples/dash-if-reference-player/index.html
2. Attempt to play any protected media.

Observed behaviour

TypeError thrown.

Console output

Stream.js:500 Uncaught TypeError: Cannot read property 'getType' of undefined
    at checkIfInitializationCompleted (Stream.js:500)
    at initializeMedia (Stream.js:460)
    at Object.activate (Stream.js:109)
    at activateStream (StreamController.js:455)
    at MediaSource.onMediaSourceOpen (StreamController.js:438)

This is occurring because the first call to protectionController.initializeForMedia(streamProcessors[i].getMediaInfo()); in checkIfInitializationCompleted causes Stream.reset to be called due to the insecure origin, but the loop continues to iterate and dereferences streamProcessors which has been cleared.

This does not happen in 2.6.6.

[davemevans]

That code introduced in #2450.