code completion for dynamic type elements

pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart

Index: pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart b/pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart
index 87ae27c618fa7c0b401792e8609017edf7602af5..f1e7198937ac0e13e794be23acb3b9497e1f46b8 100644
--- a/pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart
+++ b/pkg/analysis_server/lib/src/services/completion/dart_completion_cache.dart
@@ -66,6 +66,11 @@ class DartCompletionCache extends CompletionCache {
    */
   Map<String, ClassElement> importedClassMap;
 
+  /**
+   * The [ClassElement] for Object.
+   */
+  ClassElement _objectClassElement;
+
   DartCompletionCache(AnalysisContext context, Source source)
       : super(context, source);
 
@@ -132,6 +137,7 @@ class DartCompletionCache extends CompletionCache {
       }
       addSuggestion(elem, CompletionRelevance.DEFAULT);
     });
+    _objectClassElement = importedClassMap['Object'];
 
     /*
      * Don't wait for search of lower relevance results to complete.
@@ -159,6 +165,20 @@ class DartCompletionCache extends CompletionCache {
   }
 
   /**
+   * Return the [ClassElement] for Object.
+   */
+  ClassElement get objectClassElement {
+    if (_objectClassElement == null) {
+      Source coreUri = context.sourceFactory.forUri('dart:core');
+      LibraryElement coreLib = context.getLibraryElement(coreUri);
+      Namespace coreNamespace =
+          new NamespaceBuilder().createPublicNamespaceForLibrary(coreLib);
+      _objectClassElement = coreNamespace.definedNames['Object'];
+    }
+    return _objectClassElement;
+  }
+
+  /**
    * Return `true` if the import information is cached for the given
    * compilation unit.
    */