Fix issue 3620
Fix issue 3620

Logic in Path::arc() determines what angle should be passed to Skia for the newly-drawn arc. This was buggy in the case of drawing clockwise arcs where the start angle is greater than the end angle (on an absolute scale). Specifically, some schmuck named jhaas used a minus sign where a plus sign would have worked much better. Honestly I'm flabbergasted this hasn't shown up earlier than this.

Review URL: http://codereview.chromium.org/13756

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@6828 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser