remove internal streaming of results, remove obsolete test, cleanup unused code

pkg/analysis_server/test/completion_test_support.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 test.completion.support;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analyzer/src/generated/java_core.dart';
 import 'package:unittest/unittest.dart';
 
 import 'domain_completion_test.dart';
 
 /**
  * A base class for classes containing completion tests.
  */
-class CompletionTestCase extends CompletionTest {
+class CompletionTestCase extends CompletionDomainHandlerTest {
   static const String CURSOR_MARKER = '!';
 
   List get suggestedCompletions => suggestions
       .map((CompletionSuggestion suggestion) => suggestion.completion)
       .toList();
 
   void assertHasCompletion(String completion) {
     int expectedOffset = completion.indexOf(CURSOR_MARKER);
     if (expectedOffset >= 0) {
       if (completion.indexOf(CURSOR_MARKER, expectedOffset + 1) >= 0) {
@@ skipping 168 matching lines @@
         err.write("No results for tests:");
         for (String ch in badResults) {
           err..write(' ')..write(ch);
         }
       }
       throw new IllegalStateException(err.toString());
     }
     return tests.values.toList();
   }
 }