dash: Take remove target into account for icon size

Previously the icon size was only adjusted due to changes in the list
of application icons displayed, not when showing or hiding the remove
target. As a result, the remove target could end up cut off, so take
this case into account and adjust the icon size when showing or hiding
the remove target.

https://bugzilla.gnome.org/show_bug.cgi?id=636156

js/ui/dash.js

@@ -140,6 +140,7 @@ Dash.prototype = {
         this._clearDragPlaceholder();
         if (this._favRemoveTarget) {
             this._favRemoveTarget.actor.destroy();
+            this._adjustIconSize();
             this._favRemoveTarget = null;
         }
         DND.removeMonitor(this._dragMonitor);
@@ -164,6 +165,7 @@ Dash.prototype = {
                 this._favRemoveTarget = new RemoveFavoriteIcon();
                 this._favRemoveTarget.icon.setIconSize(this._iconSize);
                 this._box.add(this._favRemoveTarget.actor);
+                this._adjustIconSize();
         }
 
         let favRemoveHovered = false;