GitLab

This changes the Android port of Chrome to depend on the pref
kSyncSessionsGUID to be set before the SessionModelAssociator is
initialized.

We now also force-removes any foreign sessions that are using the
current client's GUID as a session tag.

This also lead to the removal of the Android specific session utils.

BUG=157419


Review URL: https://chromiumcodereview.appspot.com/11414013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@171109 0039d316-1c4b-4281-b951-d872f2087c98