De-duplicate "actor contains actor" code

Add _st_actor_contains() in st-private for use within St, and
monkey-patch in a Clutter.Actor.contains() for use by javascript, and
then replace all the duplicate implementations with one or the other
of those.

https://bugzilla.gnome.org/show_bug.cgi?id=621197

js/ui/chrome.js

@@ -65,15 +65,6 @@ Chrome.prototype = {
             children[i].allocate_preferred_size(flags);
     },
 
-    _verifyAncestry: function(actor, ancestor) {
-        while (actor) {
-            if (actor == ancestor)
-                return true;
-            actor = actor.get_parent();
-        }
-        return false;
-    },
-
     // addActor:
     // @actor: an actor to add to the chrome layer
     // @params: (optional) additional params
@@ -195,7 +186,7 @@ Chrome.prototype = {
     },
 
     _actorReparented: function(actor, oldParent) {
-        if (!this._verifyAncestry(actor, this.actor))
+        if (!this.actor.contains(actor))
             this._untrackActor(actor);
     },
 

js/ui/dash.js

@@ -275,16 +275,7 @@ SearchEntry.prototype = {
 
     _onCapturedEvent: function(actor, event) {
         let source = event.get_source();
-        let panelEvent = false;
-
-        if (source) {
-            let parent = source;
-            do {
-                if (parent == Main.panel.actor)
-                    break;
-            } while ((parent = parent.get_parent()) != null);
-            panelEvent = (parent != null);
-        }
+        let panelEvent = source && Main.panel.actor.contains(source);
 
         switch (event.type()) {
             case Clutter.EventType.BUTTON_PRESS:

js/ui/environment.js

@@ -1,5 +1,6 @@
 /* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */
 
+const Clutter = imports.gi.Clutter;;
 const Shell = imports.gi.Shell;
 const St = imports.gi.St;
 const Gettext_gtk20 = imports.gettext.domain('gtk20');
@@ -70,6 +71,12 @@ function init() {
     _patchContainerClass(St.BoxLayout);
     _patchContainerClass(St.Table);
 
+    Clutter.Actor.prototype.contains = function(child) {
+        while (child != null && child != this)
+            child = child.get_parent();
+        return child != null;
+    };
+
     _blockMethod('Clutter.Event.get_state', 'Shell.get_event_state',
                  'gjs\'s handling of Clutter.ModifierType is broken. See bug 597292.');
     _blockMethod('Gdk.Display.get_pointer', 'global.get_pointer',

js/ui/popupMenu.js

@@ -494,28 +494,17 @@ PopupMenuManager.prototype = {
             this.ungrab();
     },
 
-    _containsActor: function(container, actor) {
-        let parent = actor;
-        while (parent != null) {
-            if (parent == container)
-                return true;
-            parent = parent.get_parent();
-        }
-        return false;
-    },
-
     _eventIsOnActiveMenu: function(event) {
         let src = event.get_source();
         return this._activeMenu != null
-                && (this._containsActor(this._activeMenu.actor, src) ||
-                    this._containsActor(this._activeMenu.sourceActor, src));
+                && (this._activeMenu.actor.contains(src) ||
+                    this._activeMenu.sourceActor.contains(src));
     },
 
     _eventIsOnAnyMenuSource: function(event) {
         let src = event.get_source();
         for (let i = 0; i < this._menus.length; i++) {
-            let actor = this._menus[i].sourceActor;
-            if (this._containsActor(actor, src))
+            if (this._menus[i].sourceActor.contains(src))
                 return true;
         }
         return false;

js/ui/telepathyClient.js

@@ -629,11 +629,8 @@ Notification.prototype = {
             return false;
 
         let source = event.get_source ();
-        while (source) {
-            if (source == notification)
-                return false;
-            source = source.get_parent();
-        }
+        if (source && notification.contains(source))
+            return false;
 
         // @source is outside @notification, which has to mean that
         // we have a pointer grab, and the user clicked outside the