Change back from using NSRectFillWithOperation to plain NSRectFill because according to shark we were spending a lot of time doing  the alpha blending that we didn't need. In fact we didn't even want it because it was leaving us artifacts in the corners of our windows.
Change back from using NSRectFillWithOperation to plain NSRectFill
because according to shark we were spending a lot of time doing 
the alpha blending that we didn't need. In fact we didn't even
want it because it was leaving us artifacts in the corners of our
windows.

BUG=24490,24500
TEST=none

Review URL: http://codereview.chromium.org/273015

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@28673 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