Revert of [chromedriver] Remove invalid assertions from tests.

chrome/test/chromedriver/test/run_py_tests.py

Index: chrome/test/chromedriver/test/run_py_tests.py
diff --git a/chrome/test/chromedriver/test/run_py_tests.py b/chrome/test/chromedriver/test/run_py_tests.py
index b4d6936fe4723f7d47085a60375cc435d5e01046..f7fd8521a6927281b1e4dc9343f589caf5c93bdd 100755
--- a/chrome/test/chromedriver/test/run_py_tests.py
+++ b/chrome/test/chromedriver/test/run_py_tests.py
@@ -1219,6 +1219,7 @@
 
   def testCanSwitchToPrintPreviewDialog(self):
     old_handles = self._driver.GetWindowHandles()
+    self.assertEquals(1, len(old_handles))
     self._driver.ExecuteScript('setTimeout(function(){window.print();}, 0);')
     new_window_handle = self.WaitForNewWindow(self._driver, old_handles)
     self.assertNotEqual(None, new_window_handle)
@@ -1650,9 +1651,9 @@
     app_path = os.path.join(_TEST_DATA_DIR, 'test_app')
     driver = self.CreateDriver(chrome_switches=['load-extension=%s' % app_path])
     old_handles = driver.GetWindowHandles()
+    self.assertEqual(1, len(old_handles))
     driver.LaunchApp('gegjcdcfeiojglhifpmibkadodekakpc')
-    new_window_handle = self.WaitForNewWindow(
-        driver, old_handles, check_closed_windows=False)
+    new_window_handle = self.WaitForNewWindow(driver, old_handles)
     driver.SwitchToWindow(new_window_handle)
     body_element = driver.FindElement('tag name', 'body')
     self.assertEqual('It works!', body_element.GetText())