desktop-shell: Make activate_binding take a view instead of surface

In preparation for further refactoring. This patch also removes a
redundant NULL check. Since we pass views, and views will always have an
associated surface, there is no point of checking if it has.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
index 3eb3f5c..6ab134a 100644
--- a/desktop-shell/shell.c
+++ b/desktop-shell/shell.c
@@ -5184,12 +5184,12 @@
 static void
 activate_binding(struct weston_seat *seat,
 		 struct desktop_shell *shell,
-		 struct weston_surface *focus)
+		 struct weston_view *focus_view)
 {
+	struct weston_surface *focus;
 	struct weston_surface *main_surface;
 
-	if (!focus)
-		return;
+	focus = focus_view->surface;
 
 	if (is_black_surface(focus, &main_surface))
 		focus = main_surface;
@@ -5210,7 +5210,7 @@
 	if (pointer->focus == NULL)
 		return;
 
-	activate_binding(pointer->seat, data, pointer->focus->surface);
+	activate_binding(pointer->seat, data, pointer->focus);
 }
 
 static void
@@ -5222,7 +5222,7 @@
 	if (touch->focus == NULL)
 		return;
 
-	activate_binding(touch->seat, data, touch->focus->surface);
+	activate_binding(touch->seat, data, touch->focus);
 }
 
 static void