Add tab.StopAllServiceWorkers()

telemetry/telemetry/internal/browser/tab.py

Index: telemetry/telemetry/internal/browser/tab.py
diff --git a/telemetry/telemetry/internal/browser/tab.py b/telemetry/telemetry/internal/browser/tab.py
index 2d00c0f536a6024c053fe00203867f7b62e071ee..120301dfe6f32d37516ef766ff3403522b8c2f08 100644
--- a/telemetry/telemetry/internal/browser/tab.py
+++ b/telemetry/telemetry/internal/browser/tab.py
@@ -285,3 +285,11 @@ class Tab(web_contents.WebContents):
       exceptions.StoryActionError
     """
     return self._inspector_backend.ClearDataForOrigin(url, timeout)
+
+  def StopAllServiceWorkers(self, timeout=DEFAULT_TAB_TIMEOUT):
+    """Stops all service workers.
+
+    Raises:
+      exceptions.StoryActionError
+    """
+    return self._inspector_backend.StopAllServiceWorkers(timeout)