[LayoutNG] remove obsolete rebaseline

Bug: 635619
Change-Id: Id3063b1b1c5f31bb3678c30ecca792333424cee1
Reviewed-on: https://chromium-review.googlesource.com/c/1482595
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634578}

third_party/blink/web_tests/flag-specific/enable-blink-features=LayoutNG/http/tests/loading/nested_bad_objects-expected.txt

-main frame - didStartProvisionalLoadForFrame
-main frame - didCommitLoadForFrame
-main frame - didReceiveTitle: 
-main frame - didFinishDocumentLoadForFrame
-main frame - didHandleOnloadEventsForFrame
-main frame - didFinishLoadForFrame
- PASS - nested image objects with bad mimetype do not cause a crash.