Reorganize InheritedRefenenceContributor to serve angular completion

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 174 matching lines @@
       _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 ||
-            _opType.includeTypeNameSuggestions ||
-            _opType.includeVoidReturnSuggestions ||
-            _opType.includeConstructorSuggestions);
+    return opType.includeIdentifiers;
   }
 
   @override
   LibraryElement get libraryElement {
     //TODO(danrubel) build the library element rather than all the declarations
     CompilationUnit unit = target.unit;
     if (unit != null) {
       CompilationUnitElement elem = unit.element;
       if (elem != null) {
         return elem.library;
@@ skipping 326 matching lines @@
           if (start <= requestOffset && requestOffset <= end) {
             // Replacement range for import URI
             return new ReplacementRange(start, end - start);
           }
         }
       }
     }
     return new ReplacementRange(requestOffset, 0);
   }
 }