Roll libvpx 254786:255744

BUG=350540

Review URL: https://codereview.chromium.org/191883002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255815 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255816 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255816
Do not initialize the volume manager for sign in profiles.

Since the volumes are not used, and moreover some of them are shared between profiles, they volumes should not be mounted, and observers shouldn't be added.

TEST=Tested manually on a enterprise enrolled device.
BUG=349298

Review URL: https://codereview.chromium.org/190403002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255817 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255817