add code completion cache

pkg/analysis_server/lib/src/get_handler.dart

 // Copyright (c) 2014, 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 get.handler;
 
 import 'dart:convert';
 import 'dart:io';
 import 'dart:math';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/domain_completion.dart';
-import 'package:analysis_server/src/services/completion/completion_manager.dart';
 import 'package:analysis_server/src/socket_server.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 import 'analysis_server.dart';
 
 /**
  * Instances of the class [GetHandler] handle GET requests.
@@ skipping 380 matching lines @@
       if (header) {
         response.write('</th>');
       } else {
         response.write('</td>');
       }
     }
     ;
     response.write('</tr>');
   }
 }