Remove the newline from PyAuto login automation error message.

chrome/test/pyautolib/pyauto.py

Index: chrome/test/pyautolib/pyauto.py
diff --git a/chrome/test/pyautolib/pyauto.py b/chrome/test/pyautolib/pyauto.py
index b056bd536fe277ec471a231bbf5ba639a3468363..3cf70340285ca01e618f72c2e5c1fcf7e7c3a91d 100755
--- a/chrome/test/pyautolib/pyauto.py
+++ b/chrome/test/pyautolib/pyauto.py
@@ -4715,9 +4715,9 @@ class PyUITest(pyautolib.PyUITestBase, unittest.TestCase):
       # GAIA authentication.
       self.GetNextEvent()
     except JSONInterfaceError as e:
-      raise JSONInterfaceError('%s\nLogin failed. Perhaps Chrome crashed, '
+      raise JSONInterfaceError('Login failed. Perhaps Chrome crashed, '
                                'failed to start, or the login flow is '
-                               'broken?' % str(e))
+                               'broken? Error message: %s' % str(e))
 
   def Logout(self):
     """Log out from ChromeOS and wait for session_manager to come up.