[Telemetry] Move from telemetry WaitFor to py_utils WaitFor

telemetry/telemetry/internal/backends/chrome/tab_list_backend.py

Index: telemetry/telemetry/internal/backends/chrome/tab_list_backend.py
diff --git a/telemetry/telemetry/internal/backends/chrome/tab_list_backend.py b/telemetry/telemetry/internal/backends/chrome/tab_list_backend.py
index 61c75ffc78a30e19f3dd190bc2c060a60d42566e..36e38e3d49fdb9bd61ffaed9ca172ae434442e91 100644
--- a/telemetry/telemetry/internal/backends/chrome/tab_list_backend.py
+++ b/telemetry/telemetry/internal/backends/chrome/tab_list_backend.py
@@ -5,10 +5,11 @@
 import json
 
 from telemetry.core import exceptions
-from telemetry.core import util
 from telemetry.internal.backends.chrome_inspector import inspector_backend_list
 from telemetry.internal.browser import tab
 
+import py_utils
+
 
 class TabUnexpectedResponseException(exceptions.DevtoolsTargetCrashException):
   pass
@@ -48,7 +49,7 @@ class TabListBackend(inspector_backend_list.InspectorBackendList):
       devtools_http.DevToolsClientConnectionError
       devtools_client_backend.TabNotFoundError
       TabUnexpectedResponseException
-      exceptions.TimeoutException
+      py_utils.TimeoutException
     """
     assert self._browser_backend.supports_tab_control
     # TODO(dtu): crbug.com/160946, allow closing the last tab on some platforms.
@@ -63,7 +64,7 @@ class TabListBackend(inspector_backend_list.InspectorBackendList):
           app=self._browser_backend.browser,
           msg='Received response: %s' % response)
 
-    util.WaitFor(lambda: tab_id not in self.IterContextIds(), timeout=5)
+    py_utils.WaitFor(lambda: tab_id not in self.IterContextIds(), timeout=5)
 
   def ActivateTab(self, tab_id, timeout=30):
     """Activates the tab with the given debugger_url.