Update gyp, keep VS 2008 default for Windows builds.

bleeding_edge/dart/tools/generate_projects.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2011, 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.
 
 import os
 import sys
 import platform
 
@@ skipping 50 matching lines @@
   if platform.system() == 'Linux':
     # We need to fiddle with toplevel-dir to work around a GYP bug
     # that breaks building v8 from compiler/dart.gyp.
     args += ['--toplevel-dir', os.curdir]
     args += ['--generator-output', project_src]
   else:
     # On at least the Mac, the toplevel-dir should be where the
     # sources are. Otherwise, Xcode won't show sources correctly.
     args += ['--toplevel-dir', project_src]
 
+  if sys.platform == 'win32':
+    # Generate Visual Studio 2008 compatible files by default.
+    if not os.environ.get('GYP_MSVS_VERSION'):
+      args.extend(['-G', 'msvs_version=2008'])
+
   # Change into the dart directory as we want the project to be rooted here.
   # Also, GYP is very sensitive to exacly from where it is being run.
   os.chdir(dart_src)
 
   args += [GetProjectGypFile(project_src)]
 
   # Generate the projects.
   sys.exit(gyp.main(args))