Re-enable PasswordValueAccessible except on Windows

This test is only flaky on Windows. Re-enabling on all other platforms.

BUG=163072
TBR=vabr@chromium.org

Review URL: https://codereview.chromium.org/177923002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252917 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252917