ihf@: Could you plz help triage this bug?

More on build details:
https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8944310939516821184

This has nothing to do with ARC++. From the log files, the test fails to log into Chrome as guest. Can you bisect why Chrome is broken? The test runs quickly and this happens on all devices.

graphics_Idle.py", line 46

        with chrome.Chrome(
                logged_in=False, extra_browser_args=['--kiosk'],
                arc_mode=arc_mode):


  File "/usr/local/autotest/common_lib/test.py", line 831, in _call_test_function
    return func(*args, **dargs)
  File "/usr/local/autotest/common_lib/test.py", line 495, in execute
    dargs)
  File "/usr/local/autotest/common_lib/test.py", line 362, in _call_run_once_with_retry
    postprocess_profiled_run, args, dargs)
  File "/usr/local/autotest/common_lib/test.py", line 400, in _call_run_once
    self.run_once(*args, **dargs)
  File "/usr/local/autotest/tests/graphics_Idle/graphics_Idle.py", line 46, in run_once
    arc_mode=arc_mode):
  File "/usr/local/autotest/common_lib/cros/chrome.py", line 179, in __init__
    self._browser = self._browser_to_create.Create()
  File "/usr/local/telemetry/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome/cros_browser_finder.py", line 101, in Create
    browser_backend, self._platform_backend, startup_args)
  File "/usr/local/telemetry/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome/cros_browser_with_oobe.py", line 14, in __init__
    backend, platform_backend, startup_args)
  File "/usr/local/telemetry/src/third_party/catapult/telemetry/telemetry/internal/browser/browser.py", line 48, in __init__
    self._browser_backend.Start(startup_args, startup_url=startup_url)
  File "/usr/local/telemetry/src/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 "/usr/local/telemetry/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome/cros_browser_backend.py", line 87, in Start
    self.oobe.NavigateGuestLogin()
  File "/usr/local/telemetry/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome/cros_browser_backend.py", line 169, in oobe
    return self.misc_web_contents_backend.GetOobe()
  File "/usr/local/telemetry/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome/misc_web_contents_backend.py", line 30, in GetOobe
    return self[0]
  File "/usr/local/telemetry/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend_list.py", line 64, in __getitem__
    return self.GetBackendFromContextId(context_id)
  File "/usr/local/telemetry/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend_list.py", line 78, in GetBackendFromContextId
    raise e

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3678ed8e62512acb4ed1f3755c0591130e104ada

commit 3678ed8e62512acb4ed1f3755c0591130e104ada
Author: Muyuan Li <muyuanli@chromium.org>
Date: Sun Jun 10 21:59:22 2018

Revert "[DevTools] Respect kDisallowedForForceInstalledExtensions policy value"

This reverts commit 884aeb2e2d562191db63c99640b0c171a71f7775.

Reason for revert:
Breaking Chrome on ChromeOS PFQ:
https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8944113162689306768

Locally confirmed by reverting this CL.

BUG= 851017 

Original change's description:
> [DevTools] Respect kDisallowedForForceInstalledExtensions policy value
> 
> Added a helper to ChromeDevToolsManagerDelegate and DevToolsWindow
> to check whether inspection is allowed. This helper is used to:
> - not open DevToolsWindow;
> - not show "Inspect Element" context menu item;
> - disable DevTools-related browser commands;
> - not show inspectable views on chrome://extensions;
> - not show extensions on chrome://inspect.
> 
> RenderFrameDevToolsAgentHost also disallows attaching a debugging session
> when embedder says so to prevent exposure over protocol or remote debugging.
> 
> Bug: 838146
> Test: browser_tests --gtest_filter=DevToolsSanity*Policy*
> 
> Change-Id: I59f255cc89919f2568170f4854955ba95eadae7f
> Reviewed-on: https://chromium-review.googlesource.com/1069411
> Reviewed-by: Avi Drissman <avi@chromium.org>
> Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
> Reviewed-by: Pavol Marko <pmarko@chromium.org>
> Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
> Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#565351}

TBR=avi@chromium.org,dgozman@chromium.org,skuhne@chromium.org,rdevlin.cronin@chromium.org,pfeldman@chromium.org,poromov@chromium.org,pmarko@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 838146
Change-Id: I36768844f3c4f95a3358510b24da22c718bd9651
Reviewed-on: https://chromium-review.googlesource.com/1094734
Reviewed-by: Muyuan Li <muyuanli@chromium.org>
Commit-Queue: Muyuan Li <muyuanli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565913}
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/devtools/chrome_devtools_manager_delegate.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/devtools/chrome_devtools_manager_delegate.h
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/devtools/devtools_sanity_browsertest.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/devtools/devtools_targets_ui.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/devtools/devtools_window.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/devtools/devtools_window.h
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/extensions/api/developer_private/inspectable_views_finder.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/profiles/profile_manager.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/renderer_context_menu/render_view_context_menu.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/renderer_context_menu/render_view_context_menu.h
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/ui/browser.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/ui/browser_command_controller.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/chrome/browser/ui/browser_command_controller_unittest.cc
[delete] https://crrev.com/02a08e61e3534ed3afd30d871431a0346febe1ee/chrome/test/data/devtools/extensions/options.crx
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/content/browser/devtools/render_frame_devtools_agent_host.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/content/public/browser/devtools_manager_delegate.cc
[modify] https://crrev.com/3678ed8e62512acb4ed1f3755c0591130e104ada/content/public/browser/devtools_manager_delegate.h

is this bug fixed now as a result of the changes mentioned?

Could you please update to indicate the proper Component sub-category within "Infra"?

Thanks.