This fix is created to avoid having to rebuild all the WebRTC
Git mirrors since they're configured to sync with the http URL
instead of https (resulting in git-svn-id Git footers with the
http URL in the commit messages). Without rewriting this, it is
not possible to commit to SVN since Google code disallows committing
to a http URL.

BUG=412012
TEST=Created a CL using a Git repo like this (both before and after landing https://webrtc-codereview.appspot.com/32569004):
git clone https://chromium.googlesource.com/external/webrtc.git
cd webrtc
git auto-svn
git checkout master
git checkout -b test
(edit whitespace change)
git commit -am "Whitespace edit
git cl upload --bypass-hooks"
git cl dcommit

R=agable@chromium.org, machenbach@chromium.org, mmoss@chromium.org

Review URL: https://codereview.chromium.org/760903004

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@293171 0039d316-1c4b-4281-b951-d872f2087c98