Add pyauto commands to access local state.

chrome/test/pyautolib/prefs_info.py

 #!/usr/bin/python
 
 # Copyright (c) 2010 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.
 
 """Python representation for Chromium Preferences.
 
-Obtain one of these from PyUITestSuite::GetPrefsInfo() call.
+Obtain one of these from a call to PyUITestSuite::GetPrefsInfo() or

[Nirnimesh, 2011/05/24 19:49:02]

s/GetLocalStateInfo/GetLocalStatePrefsInfo/

Actually it should be "PyUITest::GetPrefsInfo() or
PyUITest::GetLocalStatePrefsInfo()" (I know it was wrong initially)

[Miranda Callahan, 2011/05/24 20:42:34]

Done.

+PyUITestSuite::GetLocalStateInfo().
 
 Example:
 class MyTest(pyauto.PyUITest):
   def testBasic(self):
     info = self.GetPrefsInfo()  # fetch prefs snapshot
     print info.Prefs()  # all prefs
     print info.Prefs('session.restore_on_startup')  # a single pref
 
 See more tests in chrome/test/functional/prefs.py.
 """
@@ skipping 72 matching lines @@
           list or a plain value.
       None, if prefernece for path not found (if path is given).
     """
     all = self.prefsdict.get('prefs', {})
     if not path:  # No path given. Return all prefs.
       return all
     for part in path.split('.'):  # Narrow down to the requested prefs path.
       all = all.get(part)
       if all is None: return None
     return all