Revert of Introduce ash mojo interface for lock screen action handlers

ash/public/interfaces/tray_action.mojom

Index: ash/public/interfaces/tray_action.mojom
diff --git a/ash/public/interfaces/tray_action.mojom b/ash/public/interfaces/tray_action.mojom
deleted file mode 100644
index 63c5f691a60f5bfc8792545bd111105e6839a3e8..0000000000000000000000000000000000000000
--- a/ash/public/interfaces/tray_action.mojom
+++ /dev/null
@@ -1,51 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-module ash.mojom;
-
-// An action handler state.
-enum TrayActionState {
-  // The action cannot be handled - due to no client being set, the client not
-  // supporting the action, user session not being locked etc.
-  kNotAvailable,
-  
-  // The client supports the action and is not currently handling the action.
-  kAvailable,
-
-  // The client received the request for the action and it is launching the
-  // flow to handle it.
-  kLaunching,
-
-  // The client is currently handling the action.
-  kActive,
-
-  // The client is currently handling the action, but in background (e.g. the
-  // handler window for the lock screen action was moved to the background and
-  // appears underneath the login user pods).
-  kBackground,
-};
-
-// Used by a client (e.g. Chrome) to set up a handler for a tray action, and
-// notify ash on the action handler's state changes. A tray action is one of
-// predefined actions (currently only the "new note on lock screen" action is
-// supported) that appear as an ash status area button if the client declares
-// the action as available. Clicking the button invokes a client method that
-// requests the action associated with the button to be handled.
-interface TrayAction {
-  // Sets the client to be used to handle action requests.
-  // |lock_screen_note_state|: The current lock screen note action state
-  //     associated with the client.
-  SetClient(TrayActionClient client, TrayActionState lock_screen_note_state);
-
-  // Updates action state for the lock screen note action. If called with no
-  // client set, the state change will not take effect until a client is set.
-  // Null client is equivalent to kNotAvailable state.
-  UpdateLockScreenNoteState(TrayActionState state);
-};
-
-// Used by ash to request Chrome to handle an action.
-interface TrayActionClient {
-  // Requests a lock screen note action to be handled.
-  RequestNewLockScreenNote();
-};