Cloning this repository:

git clone git://gitorious.org/~jeez/qtwebkit/jeez-webkit-performance.git jeez-webkit-performance
cd jeez-webkit-performance

Add this repository as a remote to an existing local repository:

git remote add jeez-webkit-performance git://gitorious.org/~jeez/qtwebkit/jeez-webkit-performance.git
git fetch jeez-webkit-performance
git checkout -b my-local-tracking-branch jeez-webkit-performance/master_or_other_branch