cros: Rename lock_screen.mojom to login_screen.mojom

lock_screen.mojom was primarily used for interfacing with ash/login,
which (will) contain the login, lock, and user-add UI. It is not really
ideal to name this all "login" since it is more than login, but that has
been what we've been using thus far.

Alternative names:
- ash/authentication
- ash/entry
- ash/session
- ash/session_entry

Bug: 784495
Change-Id: I6f0830e21f785ffad899d5e72dba0fa7ef7b7ca5
Reviewed-on: https://chromium-review.googlesource.com/767032
Commit-Queue: Jacob Dufault <jdufault@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516875}

• ash/BUILD.gn[diff]
• ash/login/login_screen_controller.cc[Renamed from ash/login/lock_screen_controller.cc - diff]
• ash/login/login_screen_controller.h[Renamed from ash/login/lock_screen_controller.h - diff]
• ash/login/login_screen_controller_unittest.cc[Renamed from ash/login/lock_screen_controller_unittest.cc - diff]
• ash/login/mock_lock_screen_client.cc[Deleted - diff]
• ash/login/mock_login_screen_client.cc[Added - diff]
• ash/login/mock_login_screen_client.h[Renamed from ash/login/mock_lock_screen_client.h - diff]
• ash/login/ui/lock_contents_view.cc[diff]
• ash/login/ui/lock_debug_view.cc[diff]
• ash/login/ui/lock_debug_view.h[diff]
• ash/login/ui/lock_screen_sanity_unittest.cc[diff]
• ash/login/ui/login_auth_user_view.cc[diff]
• ash/metrics/login_metrics_recorder_unittest.cc[diff]
• ash/mojo_interface_factory.cc[diff]
• ash/mus/manifest.json[diff]
• ash/public/interfaces/BUILD.gn[diff]
• ash/public/interfaces/login_screen.mojom[Renamed from ash/public/interfaces/lock_screen.mojom - diff]
• ash/public/interfaces/login_user_info.mojom[diff]
• ash/shelf/login_shelf_view.cc[diff]
• ash/shelf/login_shelf_view_unittest.cc[diff]
• ash/shell.cc[diff]
• ash/shell.h[diff]
• chrome/browser/chromeos/login/lock/screen_locker.cc[diff]
• chrome/browser/chromeos/login/lock/views_screen_locker.cc[diff]
• chrome/browser/chromeos/login/lock/views_screen_locker.h[diff]
• chrome/browser/chromeos/login/screens/user_selection_screen.h[diff]
• chrome/browser/chromeos/login/user_selection_screen_proxy.cc[diff]
• chrome/browser/ui/BUILD.gn[diff]
• chrome/browser/ui/ash/lock_screen_client.cc[Deleted - diff]
• chrome/browser/ui/ash/login_screen_client.cc[Added - diff]
• chrome/browser/ui/ash/login_screen_client.h[Renamed from chrome/browser/ui/ash/lock_screen_client.h - diff]
• chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.cc[diff]
• chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.h[diff]