Add temporary code to debug windows bot failures.

pkg/analyzer/tool/task_dependency_graph/generate.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.
 
 /**
  * This file contains code to output a description of tasks and their
  * dependencies in ".dot" format.  Prior to running, the user should run "pub
  * get" in the analyzer directory to ensure that a "packages" folder exists.
  *
  * TODO(paulberry):
@@ skipping 14 matching lines @@
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer/src/generated/constant.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/sdk_io.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:path/path.dart' as path;
+import 'dart:convert';
 
 /**
  * Generate the target .dot file.
  */
 main() {
   new Driver().generateFile();
 }
 
 typedef void GetterFinderCallback(PropertyAccessorElement element);
 
@@ skipping 20 matching lines @@
 
   /**
    * Determine if the output [file] contains the expected contents.
    */
   bool checkFile() {
     String expectedContents = generateFileContents();
     String actualContents = file.readAsStringSync();
     // Normalize Windows line endings to Unix line endings so that the
     // comparison doesn't fail on Windows.
     actualContents = actualContents.replaceAll('\r\n', '\n');
+    if (expectedContents != actualContents) {
+      // Print additional information for debugging.
+      // TODO(paulberry): eliminate this when it is no longer needed.
+      print('expected: ${JSON.encode(expectedContents)}');
+      print('actual: ${JSON.encode(actualContents)}');
+    }
     return expectedContents == actualContents;
   }
 
   /**
    * Starting at [node], find all calls to registerExtension() which refer to
    * the given [extensionIdVariable], and execute [callback] for the associated
    * result descriptors.
    */
   void findExtensions(AstNode node, TopLevelVariableElement extensionIdVariable,
       void callback(descriptorName)) {
@@ skipping 97 matching lines @@
         String task = cls.name;
         AstNode buildInputsAst = cls.getMethod('buildInputs').computeNode();
         findResultDescriptors(buildInputsAst, (String input) {
           results.add(input);
           lines.add('  $input -> $task');
         });
         findResultDescriptorLists(buildInputsAst, (String input) {
           resultLists.add(input);
           lines.add('  $input -> $task');
         });
-        findResultDescriptors(cls.getField('DESCRIPTOR').computeNode(), (String out) {
+        findResultDescriptors(cls.getField('DESCRIPTOR').computeNode(),
+            (String out) {
           results.add(out);
           lines.add('  $task -> $out');
         });
       }
     }
     AstNode enginePluginAst = enginePluginUnitElement.computeNode();
     for (String resultList in resultLists) {
       lines.add('  $resultList [shape=hexagon]');
       TopLevelVariableElement extensionIdVariable = _getExtensionId(resultList);
       findExtensions(enginePluginAst, extensionIdVariable, (String extension) {
@@ skipping 134 matching lines @@
   @override
   visitIdentifier(Identifier node) {
     Element element = node.staticElement;
     if (element is PropertyAccessorElement &&
         element.isGetter &&
         element.returnType.isSubtypeOf(type)) {
       callback(element);
     }
   }
 }