Tim: can I assign to you since this is related to the modals work (we'll have to do it before we can remove the flag).

Thanks for looking into this! I'll keep an eye when the work is ready to use the flag as needed on Telemetry tests.

Adding privacy.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7c1ef68c36541addce91a689c8de5c2d3b81a9fb

commit 7c1ef68c36541addce91a689c8de5c2d3b81a9fb
Author: Timothy Loh <timloh@chromium.org>
Date: Fri Nov 17 02:50:15 2017

Add --deny-permission-prompts switch for suppressing permission prompts

This patch adds a command-line switch, --deny-permission-prompts, which
will suppress all permission prompts. This is intended for testing
purposes, where prompts (in particular modal prompts on Android) may
be irrelevant to but get in the way of tests. This is necessary for
telemetry tests, which currently fallback to infobar prompts on Android.

Bug:  762335 
Change-Id: I6ad36b81ce6404da2c5e141b5fdca2692f37af35
Reviewed-on: https://chromium-review.googlesource.com/773768
Commit-Queue: Timothy Loh <timloh@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517260}
[modify] https://crrev.com/7c1ef68c36541addce91a689c8de5c2d3b81a9fb/chrome/browser/permissions/permission_request_manager.cc
[modify] https://crrev.com/7c1ef68c36541addce91a689c8de5c2d3b81a9fb/chrome/common/chrome_switches.cc
[modify] https://crrev.com/7c1ef68c36541addce91a689c8de5c2d3b81a9fb/chrome/common/chrome_switches.h

Nice! If the chrome-side work is done, you can assign back to me to make the necessary changes in Telemetry.

Re-assigning to you, thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/catapult/+/ed32dd50b3276262cb0ce22691b8f263955b0577

commit ed32dd50b3276262cb0ce22691b8f263955b0577
Author: Juan Antonio Navarro Perez <perezju@google.com>
Date: Wed Dec 20 15:52:08 2017

[Telemetry] Use --deny-permission-prompts

Use the chrome flag --deny-permission-prompts to suppress all permission
prompts by denying them. This allows to remove a workaround that used to
turn all modal prompts into infobars so they don't block the execution
of a story.

Flag was added by:
https://chromium-review.googlesource.com/c/chromium/src/+/773768

Bug:  chromium:762335 
Change-Id: I22656df95a250c1243e2790295d84d874b070e6f
Reviewed-on: https://chromium-review.googlesource.com/836553
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Juan Antonio Navarro Pérez <perezju@chromium.org>

[modify] https://crrev.com/ed32dd50b3276262cb0ce22691b8f263955b0577/telemetry/telemetry/internal/backends/chrome/chrome_browser_backend.py
[modify] https://crrev.com/ed32dd50b3276262cb0ce22691b8f263955b0577/telemetry/telemetry/internal/browser/browser_options.py