Bug fixes and clean-up

pkg/analyzer/lib/src/plugin/engine_plugin.dart

Index: pkg/analyzer/lib/src/plugin/engine_plugin.dart
diff --git a/pkg/analyzer/lib/src/plugin/engine_plugin.dart b/pkg/analyzer/lib/src/plugin/engine_plugin.dart
index 3e6301610c21dd5d3a867e636c9a8568e6cd3dae..3b1090f6d798d62d106a46dfe8cfb32ed7f4b13b 100644
--- a/pkg/analyzer/lib/src/plugin/engine_plugin.dart
+++ b/pkg/analyzer/lib/src/plugin/engine_plugin.dart
@@ -37,13 +37,6 @@ class EnginePlugin implements Plugin {
    */
   EnginePlugin();
 
-  /**
-   * Return a list containing all of the task descriptors that were contributed.
-   */
-  List<TaskDescriptor> taskDescriptors() {
-    return taskExtensionPoint.extensions;
-  }
-
   @override
   String get uniqueIdentifier => UNIQUE_IDENTIFIER;
 
@@ -63,25 +56,40 @@ class EnginePlugin implements Plugin {
     //
     // Register Dart tasks.
     //
+    registerExtension(taskId, BuildClassConstructorsTask.DESCRIPTOR);
     registerExtension(taskId, BuildCompilationUnitElementTask.DESCRIPTOR);
     registerExtension(taskId, BuildDirectiveElementsTask.DESCRIPTOR);
     registerExtension(taskId, BuildEnumMemberElementsTask.DESCRIPTOR);
     registerExtension(taskId, BuildExportNamespaceTask.DESCRIPTOR);
-    registerExtension(taskId, BuildSourceClosuresTask.DESCRIPTOR);
     registerExtension(taskId, BuildFunctionTypeAliasesTask.DESCRIPTOR);
+    registerExtension(taskId, BuildLibraryConstructorsTask.DESCRIPTOR);
     registerExtension(taskId, BuildLibraryElementTask.DESCRIPTOR);
     registerExtension(taskId, BuildPublicNamespaceTask.DESCRIPTOR);
+    registerExtension(taskId, BuildSourceClosuresTask.DESCRIPTOR);
     registerExtension(taskId, BuildTypeProviderTask.DESCRIPTOR);
+    registerExtension(taskId, GatherUsedImportedElementsTask.DESCRIPTOR);
+    registerExtension(taskId, GatherUsedLocalElementsTask.DESCRIPTOR);
+    registerExtension(taskId, GenerateHintsTask.DESCRIPTOR);
     registerExtension(taskId, ParseDartTask.DESCRIPTOR);
     registerExtension(taskId, ResolveLibraryTypeNamesTask.DESCRIPTOR);
+    registerExtension(taskId, ResolveReferencesTask.DESCRIPTOR);
     registerExtension(taskId, ResolveUnitTypeNamesTask.DESCRIPTOR);
+    registerExtension(taskId, ResolveVariableReferencesTask.DESCRIPTOR);
     registerExtension(taskId, ScanDartTask.DESCRIPTOR);
+    registerExtension(taskId, VerifyUnitTask.DESCRIPTOR);
     //
     // Register HTML tasks.
     //
   }
 
   /**
+   * Return a list containing all of the task descriptors that were contributed.
+   */
+  List<TaskDescriptor> taskDescriptors() {
+    return taskExtensionPoint.extensions;
+  }
+
+  /**
    * Validate the given extension by throwing an [ExtensionError] if it is not a
    * valid domain.
    */