chore(tool-manager): make palette click detection fail safe

lib/features/tool-manager/ToolManager.js

@@ -83,7 +83,6 @@ ToolManager.prototype.bindEvents = function(name, events) {
   });
 
   eventBus.on(eventsToRegister, LOW_PRIORITY, function(event) {
-    var originalEvent = event.originalEvent;
 
     // We defer the de-activation of the tool to the .activate phase,
     // so we're able to check if we want to toggle off the current
@@ -92,10 +91,27 @@ ToolManager.prototype.bindEvents = function(name, events) {
       return;
     }
 
-    if (originalEvent && domClosest(originalEvent.target, '.group[data-group="tools"]')) {
+    if (isPaletteClick(event)) {
       return;
     }
 
     this.setActive(null);
   }, this);
+
 };
+
+
+// helpers ///////////////
+
+/**
+ * Check if a given event is a palette click event.
+ *
+ * @param {EventBus.Event} event
+ *
+ * @return {boolean}
+ */
+function isPaletteClick(event) {
+  var target = event.originalEvent && event.originalEvent.target;
+
+  return target && domClosest(target, '.group[data-group="tools"]');
+}