Add automated sys.stdout check.

tests/gclient_utils_test.py

Index: tests/gclient_utils_test.py
diff --git a/tests/gclient_utils_test.py b/tests/gclient_utils_test.py
index 24ec9f1a2d18acfba99e450abf3f600d46b26f4a..b81775dcec548a0cf9e0db80d2f4ed4e071cbace 100755
--- a/tests/gclient_utils_test.py
+++ b/tests/gclient_utils_test.py
@@ -110,12 +110,18 @@ class CheckCallAndFilterTestCase(GclientUtilBase):
     args = ['boo', 'foo', 'bar']
     test_string = 'ahah\naccb\nallo\naddb\n'
     self._inner(args, test_string)
+    self.checkstdout('\n________ running \'boo foo bar\' in \'bleh\'\n'
+        'ahah\naccb\nallo\naddb\n\n'
+        '________ running \'boo foo bar\' in \'bleh\'\nahah\naccb\nallo\naddb\n')
 
   def testNoLF(self):
     # Exactly as testCheckCallAndFilterAndHeader without trailing \n
     args = ['boo', 'foo', 'bar']
     test_string = 'ahah\naccb\nallo\naddb'
     self._inner(args, test_string)
+    self.checkstdout('\n________ running \'boo foo bar\' in \'bleh\'\n'
+        'ahah\naccb\nallo\naddb\n'
+        '________ running \'boo foo bar\' in \'bleh\'\nahah\naccb\nallo\naddb')
 
 
 class SplitUrlRevisionTestCase(GclientUtilBase):