[Win] Add option to reauthenticate the OS user before revealing passwords.

This CL depends on 28713002

BUG=303113

Review URL: https://codereview.chromium.org/34393007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238552 0039d316-1c4b-4281-b951-d872f2087c98
18 files changed