Also catch devtools_http.DevToolsClientConnectionError.

tools/telemetry/telemetry/core/backends/chrome/cros_unittest.py

Index: tools/telemetry/telemetry/core/backends/chrome/cros_unittest.py
diff --git a/tools/telemetry/telemetry/core/backends/chrome/cros_unittest.py b/tools/telemetry/telemetry/core/backends/chrome/cros_unittest.py
index ec718dbf880bfebeb05f0deba15e2228d489d927..aeda1d2594ef68ccff8ceb883fb857d4767c51ae 100644
--- a/tools/telemetry/telemetry/core/backends/chrome/cros_unittest.py
+++ b/tools/telemetry/telemetry/core/backends/chrome/cros_unittest.py
@@ -8,6 +8,7 @@ from telemetry import decorators
 from telemetry.core import exceptions
 from telemetry.core import util
 from telemetry.core.backends.chrome import cros_test_case
+from telemetry.core.backends.chrome_inspector import devtools_http
 
 
 class CrOSCryptohomeTest(cros_test_case.CrOSTestCase):
@@ -59,8 +60,10 @@ class CrOSLoginTest(cros_test_case.CrOSTestCase):
       extension = self._GetAutotestExtension(b)
       try:
         extension.ExecuteJavaScript('chrome.autotestPrivate.logout();')
-      except (exceptions.BrowserConnectionGoneException,
-              exceptions.BrowserGoneException):
+      # TODO(chrishenry): crbug.com/450278. DevToolsClientConnectionError
+      # should probably be caught at a lower-level.
+      except (exceptions.AppCrashException,
+              devtools_http.DevToolsClientConnectionError):
         pass
       util.WaitFor(lambda: not self._IsCryptohomeMounted(), 20)