[network] Add missing M3U media types.

While officially only `application/vnd.apple.mpegurl` and
`audio/mpegurl` are considered as media types for HLS playlists, there
are a few more media types in active use[^1]. Add these to the list of
additional text mime types.

[^1]: https://en.wikipedia.org/wiki/M3U

Fixed: 393718935
Change-Id: I961a6b41e54921cacb3c1f823c03f9c1d2df1485
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6345654
Commit-Queue: Simon Zünd <[email protected]>
Auto-Submit: Benedikt Meurer <[email protected]>
Reviewed-by: Simon Zünd <[email protected]>

Author: bmeurer

front_end/core/platform/MimeType.ts

@@ -23,14 +23,17 @@ const ADDITIONAL_TEXT_MIME_TYPES = new Set([
   'application/javascript',
   'application/json',
   'application/json+protobuf',
+  'application/mpegurl',
   'application/vnd.apple.mpegurl',
   'application/vnd.dart',
   'application/xml',
   'application/x-aspx',
   'application/x-javascript',
   'application/x-jsp',
   'application/x-httpd-php',
+  'application/x-mpegurl',
   'audio/mpegurl',
+  'audio/x-mpegurl',
 ]);
 
 /**