Fix implicit conversion of scoped_refptr<T> to T* in PasswordStoreWin.

Since PasswordStoreWin::DBHandler ends up retaining a reference,
indicate this by passing a scoped_refptr<PasswordWebDataService>.

BUG=110610

Review URL: https://codereview.chromium.org/751813002

Cr-Commit-Position: refs/heads/master@{#305367}
2 files changed