[chromedriver] Avoid calling Runtime.evaluate when a dialog is showing.

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 87ad41a41583ac2a708b5934b93f5a32042751e4..9e915c2dca214e4d579a58246335f39c8e75734c 100755
--- a/chrome/test/chromedriver/test/run_py_tests.py
+++ b/chrome/test/chromedriver/test/run_py_tests.py
@@ -862,6 +862,14 @@ class ChromeDriverTest(ChromeDriverBaseTestWithWebServer):
     except chromedriver.ChromeDriverException as e:
       self.fail('exception while calling GetLog on a closed tab: ' + e.message)
 
+  def testGetLogOnWindowWithAlert(self):
+    self._driver.Load(self.GetHttpUrlForFile('/chromedriver/empty.html'))
+    self._driver.ExecuteScript('alert("alert!");')
+    try:
+      self._driver.GetLog('browser')
+    except Exception as e:
+      self.fail(e.message)
+
   def testAutoReporting(self):
     self.assertFalse(self._driver.IsAutoReporting())
     self._driver.SetAutoReporting(True)