Clean up dart:io exceptions.

sdk/lib/_internal/dartdoc/lib/dartdoc.dart

 // Copyright (c) 2013, 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.
 
 /**
  * To generate docs for a library, run this script with the path to an
  * entrypoint .dart file, like:
  *
  *     $ dart dartdoc.dart foo.dart
  *
@@ skipping 69 matching lines @@
   final outputDir = new Directory.fromPath(path);
   if (outputDir.existsSync()) {
     outputDir.deleteSync(recursive: true);
   }
 
   try {
     // TODO(3914): Hack to avoid 'file already exists' exception thrown
     // due to invalid result from dir.existsSync() (probably due to race
     // conditions).
     outputDir.createSync();
-  } on DirectoryIOException catch (e) {
+  } on DirectoryException catch (e) {
     // Ignore.
   }
 }
 
 /**
  * Copies all of the files in the directory [from] to [to]. Does *not*
  * recursively copy subdirectories.
  *
  * Note: runs asynchronously, so you won't see any files copied until after the
  * event loop has had a chance to pump (i.e. after `main()` has returned).
@@ skipping 494 matching lines @@
 
   void endFile() {
     final outPath = outputDir.join(_filePath);
     final dir = new Directory.fromPath(outPath.directoryPath);
     if (!dir.existsSync()) {
       // TODO(3914): Hack to avoid 'file already exists' exception
       // thrown due to invalid result from dir.existsSync() (probably due to
       // race conditions).
       try {
         dir.createSync();
-      } on DirectoryIOException catch (e) {
+      } on DirectoryException catch (e) {
         // Ignore.
       }
     }
 
     writeString(new File.fromPath(outPath), _file.toString());
     _filePath = null;
     _file = null;
   }
 
   void write(String s) {
@@ skipping 1668 matching lines @@
    return '''
         <div class="mdn">
         $mdnComment
         <div class="mdn-note"><a href="$mdnUrl">from MDN</a></div>
         </div>
         ''';
   }
 
   String toString() => mdnComment;
 }