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

third_party/wayland-protocols/include/protocol/remote-shell-unstable-v1-server-protocol.h

 /* Generated by wayland-scanner 1.11.0 */
 
 #ifndef REMOTE_SHELL_UNSTABLE_V1_SERVER_PROTOCOL_H
 #define REMOTE_SHELL_UNSTABLE_V1_SERVER_PROTOCOL_H
 
 #include <stdint.h>
 #include <stddef.h>
 #include "wayland-server.h"
 
 #ifdef  __cplusplus
@@ skipping 525 matching lines @@
         void (*set_system_modal)(struct wl_client *client,
                                  struct wl_resource *resource);
         /**
          * suggests a re-layout of remote shell input area
          *
          * Suggests a surface should become non system modal.
          * @since 8
          */
         void (*unset_system_modal)(struct wl_client *client,
                                    struct wl_resource *resource);
+        /**
+         * activate surface
+         *
+         * Make surface active.
+         *
+         * @since 9
+         */
+        void (*activate)(struct wl_client *client, struct wl_resource *resource);
 };
 
 #define ZWP_REMOTE_SURFACE_V1_SET_FULLSCREEN    0
 #define ZWP_REMOTE_SURFACE_V1_UNSET_FULLSCREEN  1
 #define ZWP_REMOTE_SURFACE_V1_CLOSE     2
 #define ZWP_REMOTE_SURFACE_V1_SET_MAXIMIZED     3
 #define ZWP_REMOTE_SURFACE_V1_UNSET_MAXIMIZED   4
 #define ZWP_REMOTE_SURFACE_V1_SET_MINIMIZED     5
 #define ZWP_REMOTE_SURFACE_V1_UNSET_MINIMIZED   6
 #define ZWP_REMOTE_SURFACE_V1_SET_PINNED        7
@@ skipping 164 matching lines @@
         void (*destroy)(struct wl_client *client,
                         struct wl_resource *resource);
 };
 
 
 #ifdef  __cplusplus
 }
 #endif
 
 #endif