[chromeos] Fix Logout automation when no browser windows are present.

chrome/test/functional/chromeos_login.py

Index: chrome/test/functional/chromeos_login.py
diff --git a/chrome/test/functional/chromeos_login.py b/chrome/test/functional/chromeos_login.py
index 86bc80dde2b2127a00f1591536e2779f0175f08d..c90c65f4c4c81c3de7233004c52234caf59f310d 100755
--- a/chrome/test/functional/chromeos_login.py
+++ b/chrome/test/functional/chromeos_login.py
@@ -156,6 +156,18 @@ class ChromeosLogin(pyauto.PyUITest):
     self.Logout()
     self.testLoginToCreateNewAccount()
 
+  def testLogoutWithNoWindows(self):
+    """Verify logout when no browser windows are present."""
+    self.testGoodLogin()
+    for i in range(5):
+      self.OpenNewBrowserWindow(True)
+    for _ in range(self.GetBrowserWindowCount()):
+      self.CloseBrowserWindow(0)
+    self.assertEqual(0, self.GetBrowserWindowCount(),
+                     msg='Could not close all browser windows')
+    self.Logout()
+    self.testGoodLogin()
+
 
 if __name__ == '__main__':
   pyauto_functional.Main()