cache_type() returns the actual type.
GetCacheType() always returns net::DISK_CACHE;

Per code search:
Nothing calls cache_type
The only not-test caller for GetCacheType() is:
https://cs.chromium.org/chromium/src/net/http/http_cache_transaction.cc?rcl=f32f0b0adf54be179edcb3ea613a85ee90cd078a&l=2855

Hmm, could this cause any data issues when it comes to MEDIA_CACHE, or does that not go through there?

Anyway, seems worth cleaning up.