Add git thaw/freeze to depot_tools.

tests/git_common_test.py

 #!/usr/bin/env python
 # Copyright 2013 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.
 
 """Unit tests for git_common.py"""
 
 import binascii
 import collections
 import os
@@ skipping 110 matching lines @@
 
     def flush(self):
       self.count += 1
 
   @unittest.expectedFailure
   def testBasic(self):
     """This test is probably racy, but I don't have a better alternative."""
     fmt = '%(count)d/10'
     stream = self.FakeStream()
 
-    pp = self.gc.ProgressPrinter(fmt, enabled=True, stream=stream, period=0.01)
+    pp = self.gc.ProgressPrinter(fmt, enabled=True, fout=stream, period=0.01)
     with pp as inc:
       for _ in xrange(10):
         time.sleep(0.02)
         inc()
 
     filtered = set(x.strip() for x in stream.data)
     rslt = set(fmt % {'count': i} for i in xrange(11))
     self.assertSetEqual(filtered, rslt)
     self.assertGreaterEqual(stream.count, 10)
 
@@ skipping 41 matching lines @@
       self.repo['A'],
       self.repo['B'],
       self.repo['E'],
       self.repo['C'],
     ], ret)
     self.assertEquals(
       self.repo.run(self.gc.hash_one, 'branch_D'),
       self.repo['D']
     )
 
+  def testStream(self):
+    items = set(self.repo.commit_map.itervalues())
+
+    def testfn():
+      for line in self.gc.stream('log', '--format=%H').xreadlines():
+        line = line.strip()
+        self.assertIn(line, items)
+        items.remove(line)
+
+    self.repo.run(testfn)
+
   def testCurrentBranch(self):
     self.repo.git('checkout', 'branch_D')
     self.assertEqual(self.repo.run(self.gc.current_branch), 'branch_D')
 
   def testBranches(self):
     self.assertEqual(self.repo.run(set, self.gc.branches()),
                      set(('branch_D', 'root_A')))
 
   def testTags(self):
     self.assertEqual(set(self.repo.run(self.gc.tags)),
@@ skipping 103 matching lines @@
     self.assertEquals(self.repo.run(self.gc.upstream, 'master'), None)
     self.repo.git('checkout', '-tb', 'happybranch', 'master')
     self.assertEquals(self.repo.run(self.gc.upstream, 'happybranch'),
                       'master')
 
 
 if __name__ == '__main__':
   sys.exit(coverage_utils.covered_main(
     os.path.join(DEPOT_TOOLS_ROOT, 'git_common.py')
   ))