Enable 25% of the users use npn_with_spdy when possible,  another 25% use npn_with_http to compare performance.
Enable 25% of the users use npn_with_spdy when possible, 
another 25% use npn_with_http to compare performance.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/2683001

git-svn-id: http://src.chromium.org/svn/trunk/src@48981 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 75eb498858fdb7225d9605ccca3f496a896c24f0
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser