Bug 1373444 - Ignore exceptions during wpt test teardown, r=maja_zf

In general these exceptions are the result of something unexpected in
the environment, but shouldn't themseslves cause the test to error.

MozReview-Commit-ID: 5XjJoT4UwnC

testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py

@@ -508,10 +508,14 @@ class MarionetteRefTestExecutor(RefTestExecutor):
         self.implementation.setup(**self.implementation_kwargs)
 
     def teardown(self):
-        self.implementation.teardown()
-        handle = self.protocol.marionette.window_handles[0]
-        self.protocol.marionette.switch_to_window(handle)
-        super(self.__class__, self).teardown()
+        try:
+            self.implementation.teardown()
+            handle = self.protocol.marionette.window_handles[0]
+            self.protocol.marionette.switch_to_window(handle)
+            super(self.__class__, self).teardown()
+        except Exception as e:
+            # Ignore errors during teardown
+            self.logger.warning(traceback.traceback.format_exc(e))
 
     def is_alive(self):
         return self.protocol.is_alive
@@ -545,10 +549,10 @@ class MarionetteRefTestExecutor(RefTestExecutor):
         test_url = self.test_url(test)
 
         return ExecuteAsyncScriptRun(self.logger,
-                             self._screenshot,
-                             self.protocol,
-                             test_url,
-                             timeout).run()
+                                     self._screenshot,
+                                     self.protocol,
+                                     test_url,
+                                     timeout).run()
 
     def _screenshot(self, marionette, url, timeout):
         marionette.navigate(url)
@@ -603,8 +607,10 @@ class InternalRefTestImplementation(object):
         try:
             self.executor.protocol.marionette._send_message("reftest:teardown", {})
             self.executor.protocol.marionette.set_context(self.executor.protocol.marionette.CONTEXT_CONTENT)
-        except socket.error:
-            pass
+        except Exception as e:
+            # Ignore errors during teardown
+            self.logger.warning(traceback.traceback.format_exc(e))
+
 
 class WdspecRun(object):
     def __init__(self, func, session, path, timeout):