arc: Implement proper Arc window activation for task moving to front.

third_party/wayland-protocols/unstable/remote-shell/remote-shell-unstable-v1.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <protocol name="remote_shell_unstable_v1">
 
   <copyright>
     Copyright 2016 The Chromium Authors.
 
     Permission is hereby granted, free of charge, to any person obtaining a
     copy of this software and associated documentation files (the "Software"),
     to deal in the Software without restriction, including without limitation
     the rights to use, copy, modify, merge, publish, distribute, sublicense,
@@ skipping 20 matching lines @@
     Warning! The protocol described in this file is experimental and backward
     incompatible changes may be made. Backward compatible changes may be added
     together with the corresponding interface version bump. Backward
     incompatible changes are done by bumping the version number in the protocol
     and interface names and resetting the interface version. Once the protocol
     is to be declared stable, the 'z' prefix and the version number in the
     protocol and interface names are removed and the interface version number is
     reset.
   </description>
 
-  <interface name="zwp_remote_shell_v1" version="9">
+  <interface name="zwp_remote_shell_v1" version="10">
     <description summary="remote_shell">
       The global interface that allows clients to turn a wl_surface into a
       "real window" which is remotely managed but can be stacked, activated
       and made fullscreen by the user.
     </description>
 
     <enum name="container">
       <description summary="containers for remote surfaces">
         Determine how a remote surface should be stacked relative to other
         shell surfaces.
@@ skipping 108 matching lines @@
       <arg name="transform" type="int"/>
       <arg name="scale_factor" type="fixed"/>
       <arg name="work_area_inset_left" type="int"/>
       <arg name="work_area_inset_top" type="int"/>
       <arg name="work_area_inset_right" type="int"/>
       <arg name="work_area_inset_bottom" type="int"/>
       <arg name="layout_mode" type="uint"/>
     </event>
   </interface>
 
-  <interface name="zwp_remote_surface_v1" version="9">
+  <interface name="zwp_remote_surface_v1" version="10">
     <description summary="A desktop window">
       An interface that may be implemented by a wl_surface, for
       implementations that provide a desktop-style user interface
       and allows for remotely managed windows.
 
       It provides requests to treat surfaces like windows, allowing to set
       properties like app id and geometry.
 
       The client must call wl_surface.commit on the corresponding wl_surface
       for the remote_surface state to take effect.
@@ skipping 308 matching lines @@
 
     <!-- Version 9 additions -->
 
     <request name="set_rectangular_shadow_background_opacity" since="9">
       <description summary="suggests the window's background opacity">
         Suggests the window's background opacity when the shadow is requested.
       </description>
       <arg name="opacity" type="fixed"/>
     </request>
 
+    <!-- Version 10 additions -->
+
+    <request name="activate" since="10">
+      <description summary="make the surface active">
+        Make the surface active and bring it to the front.
+      </description>
+      <arg name="serial" type="uint" summary="the serial of the user event"/>
+    </request>
   </interface>
 
   <!-- Version 6 additions -->
 
   <interface name="zwp_notification_surface_v1" version="6">
     <description summary="A notification window">
       An interface that may be implemented by a wl_surface to host
       notification contents.
     </description>
 
     <request name="destroy" type="destructor">
       <description summary="Destroy the notification_surface">
         Unmap and destroy the notification surface.
       </description>
     </request>
   </interface>
 
 </protocol>