Add pass_through icon scroll option

Settings.ui

@@ -6780,6 +6780,7 @@
                     <items>
                       <item id="NOTHING" translatable="yes">Do nothing</item>
                       <item id="CYCLE_WINDOWS" translatable="yes">Cycle windows</item>
+                      <item id="PASS_THROUGH" translatable="yes">Same as panel</item>
                     </items>
                   </object>
                   <packing>

appIcons.js

@@ -347,8 +347,11 @@ var taskbarAppIcon = Utils.defineClass({
     },
 
     _onMouseScroll: function(actor, event) {
-        if (Me.settings.get_string('scroll-icon-action') === 'NOTHING' || 
-            (!this.window && !this._nWindows)) {
+        let scrollAction = Me.settings.get_string('scroll-icon-action');
+        
+        if (scrollAction === 'PASS_THROUGH') {
+            return this.panel._onPanelMouseScroll(actor, event);
+        } else if (scrollAction === 'NOTHING' || (!this.window && !this._nWindows)) {
             return;
         }
 

schemas/org.gnome.shell.extensions.dash-to-panel.gschema.xml

@@ -22,6 +22,7 @@
     <value value='0' nick='NOTHING'/>
     <value value='1' nick='SWITCH_WORKSPACE'/>
     <value value='2' nick='CYCLE_WINDOWS'/>
+    <value value='3' nick='PASS_THROUGH'/>
   </enum>
   <enum id='org.gnome.shell.extensions.dash-to-panel.statusAreaPosition'>
     <value value='0' nick='BUTTONSLEFT'/>