Skip test ExternalizeConstantStrings on windows (investigate crash).

runtime/tests/vm/vm.status

 # Copyright (c) 2012, 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.
 
 cc/New: Crash # Issue 6958.
 cc/TypeVariableReflection: Crash # Issue 6958.
 cc/LibraryGetClassNames: Fail # Issue 6958.
 cc/ImportLibrary5: Fail # Issue 6958.
 
 # These tests are expected to crash on all platforms.
 cc/ArrayNew_Overflow_Crash: Crash
 cc/AllocGeneric_Overflow: Crash
 
 cc/SNPrint_BadArgs: Skip
 
 [ $arch == x64 ]
 cc/IsolateInterrupt: Skip
 
 [ $system == windows && $mode == debug ]
 cc/Sleep: Pass, Fail  # Flaky on buildbot. Issue 5133.
 
 # The following section refers to the dart vm tests which live under
 # runtime/tests/vm/dart.
 
 [ $system == windows ]
 cc/Dart2JSCompileAll: Skip
+cc/ExternalizeConstantStrings: Skip
 
 [ $runtime == drt ]
 dart/isolate_mirror_local_test: Skip
 
 [ $compiler == dart2js || $compiler == dartc ]
 dart/isolate_mirror*: Skip # compilers not aware of dart:mirrors
 dart/byte_array_test: Skip # compilers not aware of byte arrays
 dart/isolate_unhandled*: Skip
 
 [ $compiler == dart2js && $minified ]
@@ skipping 14 matching lines @@
 dart/*: Skip
 
 [ $arch == simarm ]
 dart/*: Skip
 
 # TODO(ajohnsen): Fix this as part of library changes.
 [ $compiler == none ]
 cc/CustomIsolates: Skip # Bug 6890
 cc/NewNativePort: Skip # Bug 6890
 cc/RunLoop_ExceptionParent: Skip # Bug 6890