Replace scroll event trigger with new selectionRedraw event and trigger

Author: lkcampbell

src/project/ProjectManager.js

@@ -186,7 +186,7 @@ define(function (require, exports, module) {
             }
 
             // reposition the selection triangle
-            $projectTreeContainer.triggerHandler("scroll");
+            $projectTreeContainer.triggerHandler("selectionRedraw");
 
             // in-lieu of resize events, manually trigger contentChanged for every
             // FileViewController focus change. This event triggers scroll shadows

src/utils/ViewUtils.js

@@ -275,6 +275,7 @@ define(function (require, exports, module) {
 
         $listElement.on("selectionChanged", updateSelectionMarker);
         $scrollerElement.on("scroll", updateSelectionTriangle);
+        $scrollerElement.on("selectionRedraw", updateSelectionTriangle);
 
         // update immediately
         updateSelectionMarker();