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

pkg/analysis_server/test/domain_execution_test.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.domain.execution;
 
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_execution.dart';
@@ skipping 201 matching lines @@
           expect(referencedFiles, isNotNull);
           expect(referencedFiles.length, equals(2));
           expect(referencedFiles[0], equals(source6.fullName));
           expect(referencedFiles[1], equals(source7.fullName));
         }
       });
 
       ExecutionDomainHandler handler = new ExecutionDomainHandler(server);
       Request request = new ExecutionSetSubscriptionsParams(
           [ExecutionService.LAUNCH_DATA]).toRequest('0');
-      Response response = handler.handleRequest(request);
+      handler.handleRequest(request);
 
 //      controller.add(null);
       expect(unsentNotifications, isEmpty);
     });
   });
 }
 
 /**
  * A [Source] that knows it's [fullName].
  */
@@ skipping 27 matching lines @@
   @override
   Description describe(Description description) {
     return description.add('ExecutableFile($expectedFile, $expectedKind)');
   }
 
   @override
   bool matches(item, Map matchState) {
     if (item is! ExecutableFile) {
       return false;
     }
-    ExecutableFile file = item;
     return item.file == expectedFile && item.kind == expectedKind;
   }
 }