Rename various Proxy classes. Provide a Proxy interface.

tests/stub-generator/testcfg.py

 # 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 re
 import shutil
 import sys
 import tempfile
 
@@ skipping 49 matching lines @@
     shutil.rmtree(tmpdir)
 
     # Copy comments and # commands from the beginning of the source to
     # the beginning of the generated file, then copy the remaining
     # source to the end.
     d = open(dest, 'w')
     s = open(src, 'r')
     t = open(tmp, 'r')
     while True:
       line = s.readline()
-      if not (re.match('^\s+$', line) or line.startswith('//') or line.startswith('#')):
+      if not (re.match('^\s+$', line) or line.startswith('//')
+              or line.startswith('#')):
         break
       d.write(line)
     d.write(t.read())
     os.remove(tmp)
     d.write(line)
     d.write(s.read())
 
   def GetCommand(self):
     # Parse the options by reading the .dart source file.
     source = self.GetSource()
@@ skipping 41 matching lines @@
         tests.append(DartStubTestCase(self.context,
                                       test_path,
                                       join(root, f),
                                       mode,
                                       arch))
     return tests
 
 
 def GetConfiguration(context, root):
   return DartStubTestConfiguration(context, root)