GitLab

If chrome::VersionInfo::GetVersionStringModifier() returns an empty
string (which is the case for the Stable channel and any unofficial
builds), don't append a space.

R=rtenneti@chromium.org,thestig@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/420613004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285529 0039d316-1c4b-4281-b951-d872f2087c98