It was added in https://codereview.chromium.org/112503005
for https://bugs.chromium.org/p/chromium/issues/detail?id=278558 ,
but we ended up implementing the functionality in different way.

BUG=583578

Review URL: https://codereview.chromium.org/1825063003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@299433 0039d316-1c4b-4281-b951-d872f2087c98