https://sheriff-o-matic.appspot.com/chromium.perf/examine/chromium.perf.Mac%2010.11%20Perf.startup.large_profile.cold.blank_page.

https://sheriff-o-matic.appspot.com/chromium.perf/examine/chromium.perf.Mac%2010.11%20Perf.startup.large_profile.warm.blank_page.

Looks like navigation is stalling:

Traceback (most recent call last):
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/story_runner.py", line 88, in _RunStoryAndProcessErrorIfNeeded
    state.RunStory(results)
  File "/b/s/w/irRg_6bd/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/page/shared_page_state.py", line 299, in RunStory
    self._current_page.Run(self)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/page/__init__.py", line 108, in Run
    shared_state.page_test.RunNavigateSteps(self, current_tab)
  File "/b/s/w/irRg_6bd/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/page/legacy_page_test.py", line 195, in RunNavigateSteps
    page.RunNavigateSteps(action_runner)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/page/__init__.py", line 117, in RunNavigateSteps
    url, script_to_evaluate_on_commit=self.script_to_evaluate_on_commit)
  File "/b/s/w/irRg_6bd/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/actions/action_runner.py", line 177, in Navigate
    timeout_in_seconds=timeout_in_seconds))
  File "/b/s/w/irRg_6bd/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/actions/action_runner.py", line 56, in _RunAction
    action.RunAction(self._tab)
  File "/b/s/w/irRg_6bd/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/actions/navigate.py", line 23, in RunAction
    self._timeout_in_seconds)
  File "/b/s/w/irRg_6bd/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/browser/web_contents.py", line 228, in Navigate
    self._inspector_backend.Navigate(url, script_to_evaluate_on_commit, timeout)
  File "/b/s/w/irRg_6bd/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py", line 40, in inner
    inspector_backend._ConvertExceptionFromInspectorWebsocket(e)
  File "/b/s/w/irRg_6bd/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py", line 37, in inner
    return func(inspector_backend, *args, **kwargs)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py", line 176, in Navigate
    self._page.Navigate(url, script_to_evaluate_on_commit, timeout)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_page.py", line 125, in Navigate
    self.WaitForNavigate(timeout)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_page.py", line 94, in WaitForNavigate
    self._inspector_websocket.DispatchNotifications(remaining_time)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py", line 134, in DispatchNotifications
    self._Receive(timeout)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py", line 149, in _Receive
    data = self._socket.recv()
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_core.py", line 293, in recv
    opcode, data = self.recv_data()
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_core.py", line 310, in recv_data
    opcode, frame = self.recv_data_frame(control_frame)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_core.py", line 323, in recv_data_frame
    frame = self.recv_frame()
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_core.py", line 357, in recv_frame
    return self.frame_buffer.recv_frame()
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_abnf.py", line 336, in recv_frame
    self.recv_header()
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_abnf.py", line 286, in recv_header
    header = self.recv_strict(2)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_abnf.py", line 371, in recv_strict
    bytes_ = self.recv(min(16384, shortage))
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_core.py", line 427, in _recv
    return recv(self.sock, bufsize)
  File "/b/s/w/irRg_6bd/third_party/catapult/telemetry/third_party/websocket-client/websocket/_socket.py", line 83, in recv
    raise WebSocketTimeoutException(message)
TimeoutException: <unprintable TimeoutException object>