Revert "dart:io | Change File.fullPath to FileSystemEntity.resolveSymbolicLinks."

tests/standalone/io/file_test.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.
 //
 // Dart test program for testing file I/O.
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:collection';
 import 'dart:io';
@@ skipping 902 matching lines @@
   static void testOpenDirectoryAsFileSync() {
     var f = new File('.');
     try {
       f.openSync();
       Expect.fail("Expected exception opening directory as file");
     } catch (e) {
       Expect.isTrue(e is FileException);
     }
   }
 
+  static void testOpenFile() {
+    var name = getFilename("tests/vm/data/fixed_length_file");
+    var f = new File(name);
+    Expect.isTrue(f.existsSync());
+    name = f.fullPathSync();
+    var g = new File(name);
+    Expect.isTrue(g.existsSync());
+    Expect.equals(name, g.fullPathSync());
+  }
+
   static void testReadAsBytes() {
     asyncTestStarted();
     var name = getFilename("tests/vm/data/fixed_length_file");
     var f = new File(name);
     f.readAsBytes().then((bytes) {
       Expect.isTrue(new String.fromCharCodes(bytes).endsWith("42 bytes."));
       Expect.equals(42, bytes.length);
       asyncTestDone("testReadAsBytes");
     });
   }
@@ skipping 319 matching lines @@
   static testMain() {
     asyncStart();
 
     testRead();
     testReadSync();
     testReadStream();
     testLengthSync();
     testPositionSync();
     testOpenDirectoryAsFile();
     testOpenDirectoryAsFileSync();
+    testOpenFile();
     testReadAsBytesSync();
     testReadAsBytesSyncEmptyFile();
     testReadAsTextSync();
     testReadAsTextSyncEmptyFile();
     testReadAsLinesSync();
     testLastModifiedSync();
 
     createTempDirectory(() {
       testLength();
       testReadWrite();
@@ skipping 29 matching lines @@
       testRenameSync();
       testLastModified();
       asyncEnd();
     });
   }
 }
 
 main() {
   FileTest.testMain();
 }