Add logging to the incremental resolver.

pkg/analyzer/test/generated/incremental_resolver_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 engine.incremental_resolver_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
@@ skipping 2708 matching lines @@
 ''');
   }
 
   /**
    * Reset the analysis context to have the 'incremental' option set to the
    * given value.
    */
   void _resetWithIncremental(bool enable) {
     AnalysisOptionsImpl analysisOptions = new AnalysisOptionsImpl();
     analysisOptions.incremental = enable;
+    analysisOptions.incrementalLog = null;
     analysisContext2.analysisOptions = analysisOptions;
   }
 
   void _resolveUnit(String code) {
     this.code = code;
     source = addSource(code);
     oldLibrary = resolve(source);
     oldUnit = resolveCompilationUnit(source, oldLibrary);
     oldUnitElement = oldUnit.element;
   }
@@ skipping 1168 matching lines @@
     _visitList(node.metadata, other.metadata);
     _visitNode(node.identifier, other.identifier);
   }
 
   static void assertSameResolution(CompilationUnit actual,
       CompilationUnit expected) {
     _SameResolutionValidator validator = new _SameResolutionValidator(expected);
     actual.accept(validator);
   }
 }