Fix compile error in ShellDesktopController with clang

error: expected function body after function declarator
    ... outputs) OVERRIDE {

TBR=derat@chromium.org

Review URL: https://codereview.chromium.org/213283008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@259764 0039d316-1c4b-4281-b951-d872f2087c98