Use Default PasswordStore with Ozone.

Currently, we dont initialize any passwordstore with ozone platform.
This CL adds support for using DefaultPasswordStore with Ozone. 

This fixes the startup crash for Chromium with Ozone
implementations( i.e. Ozone-Wayland).

BUG=

Review URL: https://codereview.chromium.org/120413002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242633 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242633