Remove stale platform-specific expectations for fast/

As the description says, this patch removes the stale platform-specific
expectation entries for the fast subdirectory. The tests that generated
these expectations have moved or been removed.

BUG=369287
TBR=ojan

Review URL: https://codereview.chromium.org/269673003

git-svn-id: svn://svn.chromium.org/blink/trunk@173143 bbb929c8-8fbe-4397-9dbb-9b2b20218538