Remove disfunctional "always clobber" from Windows build.

utils/compiler/buildbot.py

 #!/usr/bin/python
 
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Dart2js buildbot steps
 
 Runs tests for the  dart2js compiler.
 """
@@ skipping 124 matching lines @@
     print '@@@STEP_FAILURE@@@'
   return exit_code
 
 
 def BuildSDK(mode, system):
   """ build the SDK.
    Args:
      - mode: either 'debug' or 'release'
      - system: either 'linux', 'mac', or 'win7'
   """
-  # TODO(efortuna): Currently we always clobber Windows builds. The VM
-  # team thinks there's a problem with dependency tracking on Windows that
-  # is leading to occasional build failures. Remove when this gyp issue has
-  # been ironed out.
-  if system == 'win7':
-    for build in ['Release_', 'Debug_']:
-      for arch in ['ia32', 'x64']:
-        outdir = build + arch
-        shutil.rmtree(outdir, ignore_errors=True)
-        shutil.rmtree('runtime/%s' % outdir, ignore_errors=True)
-
   os.chdir(DART_PATH)
 
   args = [sys.executable, './tools/build.py', '--mode=' + mode, 'create_sdk']
   print 'running %s' % (' '.join(args))
   return subprocess.call(args, env=NO_COLOR_ENV)
 
 
 def TestCompiler(runtime, mode, system, option, flags, is_buildbot):
   """ test the compiler.
    Args:
@@ skipping 181 matching lines @@
   if status == 0 and option != 'checked' and runtime == 'd8':
     status = TestCompiler(runtime, mode, system, option,
                           test_flags + ['--checked'], is_buildbot)
 
   if runtime != 'd8': CleanUpTemporaryFiles(system, runtime)
   if status != 0: print '@@@STEP_FAILURE@@@'
   return status
 
 if __name__ == '__main__':
   sys.exit(main())