Wrap dart:io exception in getChildren(), implement for the memory FS.

pkg/analyzer/lib/file_system/physical_file_system.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 physical_file_system;
 
 import 'dart:async';
 import 'dart:io' as io;
 
 import 'package:analyzer/src/generated/java_io.dart';
@@ skipping 62 matching lines @@
  */
 class _PhysicalFile extends _PhysicalResource implements File {
   _PhysicalFile(io.File file) : super(file);
 
   @override
   int get modificationStamp {
     try {
       io.File file = _entry as io.File;
       return file.lastModifiedSync().millisecondsSinceEpoch;
     } on io.FileSystemException catch (exception) {
-      throw new FileSystemException(path, exception.message);
+      throw new FileSystemException(exception.path, exception.message);
     }
   }
 
   @override
   Source createSource([Uri uri]) {
     io.File file = _entry as io.File;
     JavaFile javaFile = new JavaFile(file.absolute.path);
     if (uri == null) {
       uri = javaFile.toURI();
     }
@@ skipping 33 matching lines @@
 
   @override
   _PhysicalFolder getChildAssumingFolder(String relPath) {
     String canonicalPath = canonicalizePath(relPath);
     io.Directory directory = new io.Directory(canonicalPath);
     return new _PhysicalFolder(directory);
   }
 
   @override
   List<Resource> getChildren() {
-    List<Resource> children = <Resource>[];
-    io.Directory directory = _entry as io.Directory;
-    List<io.FileSystemEntity> entries = directory.listSync(recursive: false);
-    int numEntries = entries.length;
-    for (int i = 0; i < numEntries; i++) {
-      io.FileSystemEntity entity = entries[i];
-      if (entity is io.Directory) {
-        children.add(new _PhysicalFolder(entity));
-      } else if (entity is io.File) {
-        children.add(new _PhysicalFile(entity));
+    try {
+      List<Resource> children = <Resource>[];
+      io.Directory directory = _entry as io.Directory;
+      List<io.FileSystemEntity> entries = directory.listSync(recursive: false);
+      int numEntries = entries.length;
+      for (int i = 0; i < numEntries; i++) {
+        io.FileSystemEntity entity = entries[i];
+        if (entity is io.Directory) {
+          children.add(new _PhysicalFolder(entity));
+        } else if (entity is io.File) {
+          children.add(new _PhysicalFile(entity));
+        }
       }
+      return children;
+    } on io.FileSystemException catch (exception) {
+      throw new FileSystemException(exception.path, exception.message);
     }
-    return children;
   }
 
   @override
   bool isOrContains(String path) {
     if (path == this.path) {
       return true;
     }
     return contains(path);
   }
 }
@@ skipping 31 matching lines @@
   bool operator ==(other) {
     if (runtimeType != other.runtimeType) {
       return false;
     }
     return path == other.path;
   }
 
   @override
   String toString() => path;
 }