Fix expectations for navigation-timing.https.html wpt test

This is a follow-up CL of crrev.com/c/1215426. Now the test
is passing and we don't need -expected.txt files. I forgot to
remove these files under flag-specific/.

Bug: 882477
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: I7e5a3bb7bb3393bfbbf0e9827daf5c8983cff41a
Reviewed-on: https://chromium-review.googlesource.com/1218044Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590207}

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

@@ -30,10 +30,3 @@ Bug(none) http/tests/misc/redirect-to-about-blank.html [ Timeout ]
 # PlzWorker: These are tentatively failing because of unimplemented code.
 crbug.com/715632 external/wpt/fetch/sec-metadata/sharedworker.tentative.https.sub.html [ Failure ]
 crbug.com/715632 fast/workers/shared-worker-load-error.html [ Timeout ]
-
-# Navigation-timing tests Failing after recent changes
-crbug.com/882477 external/wpt/service-workers/service-worker/navigation-timing.https.html [ Failure ]
-crbug.com/882477 virtual/outofblink-cors-ns/external/wpt/service-workers/service-worker/navigation-timing.https.html [ Failure ]
-crbug.com/882477 virtual/outofblink-cors/external/wpt/service-workers/service-worker/navigation-timing.https.html [ Failure ]
-crbug.com/882477 virtual/service-worker-servicification/external/wpt/service-workers/service-worker/navigation-timing.https.html [ Failure ]
-

third_party/WebKit/LayoutTests/flag-specific/enable-features=NetworkService/external/wpt/service-workers/service-worker/navigation-timing.https-expected.txt

-This is a testharness.js-based test.
-FAIL Service worker controlled navigation timing assert_unreached: unexpected rejection: assert_true: Expected workerStart <= fetchStart expected true got false Reached unreachable code
-PASS Service worker controlled navigation timing network fallback
-PASS Service worker controlled navigation timing redirect
-Harness: the test ran to completion.
-

third_party/WebKit/LayoutTests/flag-specific/enable-features=NetworkService/virtual/navigation-mojo-response/external/wpt/service-workers/service-worker/navigation-timing.https-expected.txt

-This is a testharness.js-based test.
-FAIL Service worker controlled navigation timing assert_unreached: unexpected rejection: assert_true: Expected workerStart <= fetchStart expected true got false Reached unreachable code
-FAIL Service worker controlled navigation timing network fallback assert_unreached: unexpected rejection: assert_true: Expected workerStart <= fetchStart expected true got false Reached unreachable code
-PASS Service worker controlled navigation timing redirect
-Harness: the test ran to completion.
-