v8.browsing_mobile failing on chromium.perf/Android One Perf

Builders failed on: 
- Android One Perf: 
  https://build.chromium.org/p/chromium.perf/builders/Android%20One%20Perf


Seems to usually be v8.browsing_mobile/browse:shopping:lazada


From log:

Traceback (most recent call last):
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/story_runner.py", line 98, in _RunStoryAndProcessErrorIfNeeded
    state.WillRunStory(story)
  File "/b/swarming/w/ir/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 75, in traced_function
    return func(*args, **kwargs)
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/page/shared_page_state.py", line 248, in WillRunStory
    self._StartBrowser(page)
  File "/b/swarming/w/ir/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 75, in traced_function
    return func(*args, **kwargs)
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/page/shared_page_state.py", line 209, in _StartBrowser
    self._browser = self._possible_browser.Create(self._finder_options)
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/backends/chrome/android_browser_finder.py", line 136, in Create
    browser_backend, self._platform_backend, self._credentials_path)
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/browser/browser.py", line 60, in __init__
    self._LogBrowserInfo()
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/browser/browser.py", line 117, in _LogBrowserInfo
    logging.info('Browser started (pid=%s).', self._browser_backend.pid)
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/backends/chrome/android_browser_backend.py", line 236, in pid
    '%s' % (self._backend_settings.package, pids))
Exception: At most one instance of process org.chromium.chrome expected but found pids: defaultdict(<type 'list'>, {'org.chromium.chrome:sandboxed_process0': ['6288'], 'org.chromium.chrome': ['6257', '6333']})