cros: Convert SystemTrayDelegate::ManageBluetoothDevices to mojo for mash

ash/public/interfaces/system_tray.mojom

 // Copyright 2016 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;
 
 import "ash/public/interfaces/update.mojom";
+import "mojo/common/string16.mojom";
 
 // Allows clients (e.g. Chrome browser) to control the ash system tray menu.
 interface SystemTray {
   // Sets the client interface.
   SetClient(SystemTrayClient client);
 
   // Sets the enabled state of the tray on the primary display. If not |enabled|
   // any open menu will be closed.
   SetPrimaryTrayEnabled(bool enabled);
 
   // Sets the visibility of the tray on the primary display.
   SetPrimaryTrayVisible(bool visible);
 
   // Sets the clock to use 24 hour time formatting if |use_24_hour| is true.
   // Otherwise sets 12 hour time formatting.
   SetUse24HourClock(bool use_24_hour);
 
   // Shows an icon in the system tray indicating that a software update is
   // available. Once shown the icon persists until reboot. |severity| and
   // |factory_reset_required| are used to set the icon, color, and tooltip.
   ShowUpdateIcon(UpdateSeverity severity, bool factory_reset_required);
 };
 
 // Allows ash system tray to control a client (e.g. Chrome browser). Requests
 // often involve preferences or web UI that is not available to ash.
 interface SystemTrayClient {
   // Shows general settings UI.
   ShowSettings();
 
+  // Shows settings related to Bluetooth devices (e.g. to add a device).
+  ShowBluetoothSettings();
+
+  // Shows the web UI dialog to pair a Bluetooth device.
+  // |address| is the unique device address in the form "XX:XX:XX:XX:XX:XX"
+  // with hex digits X. |name_for_display| is a human-readable name, not
+  // necessarily the device name.
+  ShowBluetoothPairingDialog(string address,

[James Cook, 2017/03/17 22:23:30]

This method isn't called yet, but is used to generate the function signature in
SystemTrayClient() that I'll need in the next CL.

[msw, 2017/03/18 00:44:44]

Acknowledged.

+                             mojo.common.mojom.String16 name_for_display,
+                             bool paired,

[James Cook, 2017/03/17 22:23:30]

I do not know why you would show a pairing dialog if |paired| was true, but
that's how it works today.

[msw, 2017/03/18 00:44:44]

Acknowledged.

+                             bool connected);
+
   // Shows the settings related to date, timezone etc.
   ShowDateSettings();
 
   // Shows the dialog to set system time, date, and timezone.
   ShowSetTimeDialog();
 
   // Shows settings related to multiple displays.
   ShowDisplaySettings();
 
   // Shows settings related to power.
@@ skipping 47 matching lines @@
   // Shows UI for changing proxy settings.
   ShowProxySettings();
 
   // Attempts to sign out the user.
   // TODO(jamescook): Migrate to a user or login service. crbug.com/665582
   SignOut();
 
   // Attempts to restart the system for update.
   RequestRestartForUpdate();
 };