Do not apply CORB to application/x-www-form-urlencoded.

Bug: 990853, 802836
Change-Id: I7aeba7f34ae3257a8c0d7900a4f266f872273304
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1739646
Commit-Queue: Charlie Reis <[email protected]>
Auto-Submit: Łukasz Anforowicz <[email protected]>
Reviewed-by: Charlie Reis <[email protected]>
Cr-Commit-Position: refs/heads/master@{#684464}

Author: anforowicz

fetch/corb/script-resource-with-nonsniffable-types.tentative.sub.html

@@ -56,7 +56,6 @@
   "application/gzip",
   "application/x-gzip",
   "application/x-protobuf",
-  "application/x-www-form-urlencoded",
   "application/zip",
   "multipart/byteranges",
   "text/event-stream",