Resource.js has the following comment for its "enum" values to keep in sync with the real enums:
// Keep these in sync with WebCore::InspectorResource::Type
Lost sync a long time ago:
However, this was shadowed by the real bug. The type was used in _mimeTypeIsConsistentWithType and always returned true, and the problem was overlooked.
Created attachment 43548 [details]
Landed in http://trac.webkit.org/changeset/51229
r51229 = 478a626e9493ad34878c2a32025991ffaf9e8b5f