Fix 'Unused local variable' hints in analyzer and analysis_server.

pkg/analysis_server/test/integration/integration_tests.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.integration.analysis;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
@@ skipping 167 matching lines @@
 
   /**
    * If [skipShutdown] is not set, shut down the server.
    */
   Future _shutdownIfNeeded() {
     if (skipShutdown) {
       return new Future.value();
     }
     // Give the server a short time to comply with the shutdown request; if it
     // doesn't exit, then forcibly terminate it.
-    Completer processExited = new Completer();
     sendServerShutdown();
     return server.exitCode.timeout(SHUTDOWN_TIMEOUT, onTimeout: () {
       return server.kill();
     });
   }
 }
 
 final Matcher isResponse = new MatchesJsonObject('response', {
   'id': isString
 }, optionalFields: {
@@ skipping 673 matching lines @@
    */
   void _recordStdio(String line) {
     double elapsedTime = _time.elapsedTicks / _time.frequency;
     line = "$elapsedTime: $line";
     if (_debuggingStdio) {
       print(line);
     }
     _recordedStdio.add(line);
   }
 }