Network Service: Remove crash expectations for interception-file-url.js

Works for me now, I think the DCHECK it was hitting was removed as a
drive-by here:

https://chromium-review.googlesource.com/c/chromium/src/+/1008974/11/content/browser/devtools/devtools_url_loader_interceptor.cc#b478

TBR: dgozman@chromium.org, lushnikov@chromium.org
Bug: 721408,831887
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_mojo
Change-Id: I886a1e302b94b5de685e4ef4442c10564df78539
Reviewed-on: https://chromium-review.googlesource.com/1044539Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Commit-Queue: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556259}

third_party/WebKit/LayoutTests/FlagExpectations/enable-features=NetworkService

@@ -41,9 +41,7 @@ Bug(none) http/tests/security/mixedContent/filesystem-url-in-iframe.html [ Failu
 
 # Cross-Origin Read Blocking is not implemented.
 crbug.com/792546 http/tests/inspector-protocol/network/block_cross_site_document_load.js [ Failure ]
-crbug.com/792546 external/wpt/fetch/corb/img-mime-types-coverage.tentative.sub.html [ Failure ]
-crbug.com/792546 external/wpt/fetch/corb/img-png-mislabeled-as-html-nosniff.tentative.sub.html [ Failure ]
-crbug.com/792546 external/wpt/fetch/corb/preload-image-png-mislabeled-as-html-nosniff.tentative.sub.html [ Failure ]
+crbug.com/792546 external/wpt/fetch/corb/img-mime-types-coverage.tentative.sub.html [ Failure ]
+crbug.com/792546 external/wpt/fetch/corb/img-png-mislabeled-as-html-nosniff.tentative.sub.html [ Failure ]
+crbug.com/792546 external/wpt/fetch/corb/preload-image-png-mislabeled-as-html-nosniff.tentative.sub.html [ Failure ]
 crbug.com/792546 external/wpt/fetch/corb/script-html-correctly-labeled.tentative.sub.html [ Failure ]
-
-crbug.com/812464 inspector-protocol/network/interception-file-url.js [ Pass Crash ]