Windows: Fix opacity of drag images.
Windows: Fix opacity of drag images.

BUG=11457
TEST=Go to google.com, drag logo around. Preview image should now look nice.

Review URL: http://codereview.chromium.org/2963009

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@52249 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