Remove the needsSiteSpecificQuirks setting

It does nothing as of Blink r178756:
https://codereview.chromium.org/414443006

It's never set as of Chromium r289294:
https://codereview.chromium.org/449393002

BUG=401887

Review URL: https://codereview.chromium.org/453813003

git-svn-id: svn://svn.chromium.org/blink/trunk@180193 bbb929c8-8fbe-4397-9dbb-9b2b20218538
LeakExpectations: gardening. marking flaky Resource leak

http/tests/security/mixedContent/insecure-audio-video-in-main-frame.html is leaking Resource (flaky)

TBR=hajimehoshi@chromium.org,tkent@chromium.org
NOTRY=true
BUG=403367

Review URL: https://codereview.chromium.org/466373003

git-svn-id: svn://svn.chromium.org/blink/trunk@180194 bbb929c8-8fbe-4397-9dbb-9b2b20218538