Remove out-of date test expectations for Win7

fast/events/touch/gesture/touch-gesture-scroll-input-field.html no
longer fails on windows as of r178592. Remove failing expectation.

TBR=ojan@chromium.org

Review URL: https://codereview.chromium.org/412663002

git-svn-id: svn://svn.chromium.org/blink/trunk@178697 bbb929c8-8fbe-4397-9dbb-9b2b20218538