Prompt to delete pending edits before changing the Gerrit CL description.

BUG=641838

Review-Url: https://codereview.chromium.org/2318903002
diff --git a/tests/git_cl_test.py b/tests/git_cl_test.py
index 428f487..1bb517e 100755
--- a/tests/git_cl_test.py
+++ b/tests/git_cl_test.py
@@ -38,7 +38,7 @@
     return 1
   def GetDescription(self):
     return ChangelistMock.desc
-  def UpdateDescription(self, desc):
+  def UpdateDescription(self, desc, force=False):
     ChangelistMock.desc = desc
 
 
@@ -1664,7 +1664,7 @@
       # Simulate user changing something.
       return 'Some.\n\nBUG=123\n\nChange-Id: xxx'
 
-    def UpdateDescriptionRemote(_, desc):
+    def UpdateDescriptionRemote(_, desc, force=False):
       self.assertEquals(desc, 'Some.\n\nBUG=123\n\nChange-Id: xxx')
 
     self.mock(git_cl.sys, 'stdout', StringIO.StringIO())