Fixes for URI and Object completions with the new driver.

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

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library services.completion.dart.manager;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/provisional/completion/completion_core.dart'
@@ skipping 159 matching lines @@
       this.source,
       this.offset,
       CompilationUnit unit,
       this._originalRequest,
       this.performance) {
     _updateTargets(unit);
   }
 
   @override
   LibraryElement get coreLib {
-    if (_coreLib == null) {
-      Source coreUri = context.sourceFactory.forUri('dart:core');
+    if (result != null) {
+      AnalysisContext context = result.unit.element.context;
+      _coreLib = context.typeProvider.objectType.element.library;
+    } else {
+      Source coreUri = sourceFactory.forUri('dart:core');
       _coreLib = context.computeLibraryElement(coreUri);
     }
     return _coreLib;
   }
 
   @override
   bool get includeIdentifiers {
     opType; // <<< ensure _opType is initialized
     return !_opType.isPrefixed &&
         (_opType.includeReturnValueSuggestions ||
@@ skipping 23 matching lines @@
     return _objectType;
   }
 
   OpType get opType {
     if (_opType == null) {
       _opType = new OpType.forCompletion(target, offset);
     }
     return _opType;
   }
 
+  @override
+  SourceFactory get sourceFactory {
+    return context?.sourceFactory ?? result.sourceFactory;
+  }
+
   /**
    * Throw [AbortCompletion] if the completion request has been aborted.
    */
   void checkAborted() {
     _originalRequest.checkAborted();
   }
 
   @override
   Future resolveContainingExpression(AstNode node) async {
     // TODO When an Expression can be resolved instead of just an entire unit,
@@ skipping 280 matching lines @@
           if (start <= requestOffset && requestOffset <= end) {
             // Replacement range for import URI
             return new ReplacementRange(start, end - start);
           }
         }
       }
     }
     return new ReplacementRange(requestOffset, 0);
   }
 }