git_cl: Add the ability to set the description.

tests/git_cl_test.py

Index: tests/git_cl_test.py
diff --git a/tests/git_cl_test.py b/tests/git_cl_test.py
index 571be654aa717d37e5f4fa1fd8680a1529d904cd..def78e603a15e54cc40ce7ab2310671ca337c653 100755
--- a/tests/git_cl_test.py
+++ b/tests/git_cl_test.py
@@ -1423,6 +1423,47 @@ class TestGitCl(TestCase):
         'description', 'https://code.review.org/123123', '-d', '--gerrit']))
     self.assertEqual('foobar\n', out.getvalue())
 
+  def test_description_set_raw(self):
+    out = StringIO.StringIO()
+    self.mock(git_cl.sys, 'stdout', out)
+
+    set_desc = []
+    class MockChangelist():
+      def __init__(self, **kwargs):
+        pass
+      def GetIssue(self):
+        return 1
+      def GetDescription(self):
+        return 'foo'
+      def UpdateDescription(self, desc):
+        set_desc.append(desc)
+
+    self.mock(git_cl, 'Changelist', MockChangelist)
+
+    self.assertEqual(0, git_cl.main(['description', '-n', 'hihi']))
+    self.assertEqual('hihi', set_desc[0])
+
+  def test_description_set_stdin(self):
+    out = StringIO.StringIO()
+    self.mock(git_cl.sys, 'stdout', out)
+
+    set_desc = []
+    class MockChangelist():
+      def __init__(self, **kwargs):
+        pass
+      def GetIssue(self):
+        return 1
+      def GetDescription(self):
+        return 'foo'
+      def UpdateDescription(self, desc):
+        set_desc.append(desc)
+
+    self.mock(git_cl, 'Changelist', MockChangelist)
+    self.mock(git_cl.sys, 'stdin', ['hi', 'there'])
+
+    self.assertEqual(0, git_cl.main(['description', '-n', '-']))
+    self.assertEqual('hi\nthere', set_desc[0])
+
 
 if __name__ == '__main__':
   git_cl.logging.basicConfig(