Remove ArrayUtils

pkg/analyzer/lib/src/generated/element.dart

Index: pkg/analyzer/lib/src/generated/element.dart
diff --git a/pkg/analyzer/lib/src/generated/element.dart b/pkg/analyzer/lib/src/generated/element.dart
index 4270383b130fcde146d301ae6ebab5d162171720..508f9ee9a70aa45828613ed46f9647ce08ee515f 100644
--- a/pkg/analyzer/lib/src/generated/element.dart
+++ b/pkg/analyzer/lib/src/generated/element.dart
@@ -1286,13 +1286,16 @@ class ClassElementImpl extends ElementImpl implements ClassElement {
   accept(ElementVisitor visitor) => visitor.visitClassElement(this);
 
   /**
-   * Set the toolkit specific information objects attached to this class.
-   *
-   * @param toolkitObjects the toolkit objects attached to this class
+   * Add the given [toolkitObject] to the list of toolkit specific information
+   * objects attached to this class.
    */
   void addToolkitObjects(ToolkitObjectElement toolkitObject) {
     (toolkitObject as ToolkitObjectElementImpl).enclosingElement = this;
-    _toolkitObjects = ArrayUtils.add(_toolkitObjects, toolkitObject);
+    if (_toolkitObjects.isEmpty) {
+      // Convert from a non-growable list to a growable list.
+      _toolkitObjects = <ToolkitObjectElement>[];
+    }
+    _toolkitObjects.add(toolkitObject);
   }
 
   @override