Remove --webkit from trychange.py since it never really worked correctly.
Remove --webkit from trychange.py since it never really worked correctly.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/3328002

git-svn-id: bd64dd6fa6f3f0ed0c0666d1018379882b742947@58200 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

svn2github/chromium-depot-tools,svn2github/chromium-depot-tools,svn2github/chromium-depot-tools