Update LeakExpectations file.

- r255342 fixed |EventSender| context menu leak.
+ acid3 is flaky
+ http/tests/htmlimports/redirect.html flaky
+ fast/dom/remove-svg-font-face-element-crash.xhtml flaky
+ mark more shared worker tests

NOTRY=true
BUG=364390, 364391, 364395, 364408, 366455, 366477

Review URL: https://codereview.chromium.org/256503002

git-svn-id: svn://svn.chromium.org/blink/trunk@172446 bbb929c8-8fbe-4397-9dbb-9b2b20218538