Fix v4l2 video capture does not work issue.

BUG=330304

Review URL: https://codereview.chromium.org/100623015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242469 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242469