Rename abstract_context_test.dart -> abstract_context.dart

pkg/analyzer/test/src/context/abstract_context.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 test.src.task.abstract_context_test;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/context/context.dart';
 import 'package:analyzer/src/generated/element.dart';
@@ skipping 79 matching lines @@
     context.sourceFactory = new SourceFactory(<UriResolver>[
       new DartUriResolver(sdk),
       new ResourceUriResolver(resourceProvider)
     ]);
     // prepare AnalysisDriver
     analysisDriver = new AnalysisDriver(taskManager, context);
   }
 
   void tearDown() {}
 }