Unable to reproduce the issue on mac 10.12.6 and 10.13.1 using chrome reported version #65.0.3322.3 and latest canary #65.0.3323.0.

Attached a screen cast for reference.

Following are the steps followed to reproduce the issue.
------------
1. Navigated to www.zombo.com
2. Clicked on allow button to enable flash.
3. Observed that the site rendered without any issues 

jleedev@ - Could you please check the issue on latest canary #65.0.3323.0 by creating a new profile without any apps and extensions and please let us know if the issue still persist or not.

Thanks...!!

Deleted: 802276.mp4 1.9 MB

	802276.mp4 1.9 MB View Download

Yes, I created a new profile using the --user-data-dir flag. The issue persists in 65.0.3323.0, and I can reproduce this on a different Mac computer.

Restarting Chrome is necessary to reproduce this bug: When Flash player is downloaded for the first time, it seems to always run successfully, but after restarting Chrome it sometimes loads and sometimes does not (for that particular run of Chrome).

Thank you for providing more feedback. Adding requester "krajshree@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Unable to reproduce the issue on chrome stable version 65.0.3323.0 using Mac 10.13.1 with the below mentioned steps.
1. Launched chrome reported version and navigated to www.zombo.com
2. Clicked on allow button to enable flash.
3. Observed that the site rendered without any issues

@Reporter: Please find the atatched screen cast for your reference and let us know if we miss anything in reproducing this issue.

Thanks!

Deleted: 802276.mp4 2.9 MB

	802276.mp4 2.9 MB View Download

Again, this is an issue of flakiness. I can reliably reproduce this, on several computers, by restarting Chrome enough times; just once is not always enough to reproduce it.

It does, however, seem to reliably reproduce with bisect-builds.py, which brings me directly to a commit that has to do with PPAPI processes and the Mac sandbox, which strongly suggests that I'm on the right path.

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You are probably looking for a change made after 525464 (known good), but no later than 525478 (first known bad).
CHANGELOG URL:
  https://chromium.googlesource.com/chromium/src/+log/27db1b323153ae956d0702030809fb46d762225e..5cf69dfccd95c1eb49e10c61f823e1849975496a


commit	159fc4ac77b00a0c1134765d2615b6e9a2b5311b
author	Greg Kerr <kerrnel@chromium.org>

macOS V2 Sandbox: Sandbox PPAPI Processes.

This launches PPAPI processes under the new macOS V2 sandbox.

Thank you for providing more feedback. Adding requester "sc00335628@techmahindra.com" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Unable to reproduce this issue from TE end, as per comment#7 assigning this issue to Greg Kerr

You are probably looking for a change made after 525464 (known good), but no later than 525478 (first known bad).

https://chromium.googlesource.com/chromium/src/+log/27db1b323153ae956d0702030809fb46d762225e..5cf69dfccd95c1eb49e10c61f823e1849975496a
Reviewed-on: https://chromium-review.googlesource.com/830976

Suspecting same from changelog

@Greg Kerr: Please feel free to re-assign if it is not related to your change.

Thanks!

I think this is because we don't have an allow rule for the component updater directory in the user-data-dir.

The V2 sandbox being experimental also explains the flakiness.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/51462da1bd4a72aeebe0cff5bfb7038cf0310114

commit 51462da1bd4a72aeebe0cff5bfb7038cf0310114
Author: Greg Kerr <kerrnel@chromium.org>
Date: Wed Jan 31 23:14:25 2018

macOS V2 Sandbox: Add component flash player to PPAPI sandbox profile.

This adds access to the component flash player to the PPAPI sandbox
profile.

Tbr: creis@chromium.org
Bug:  802276 
Change-Id: Iddf87ef8a14c2b6ffe8950e870ea81503a415395
Reviewed-on: https://chromium-review.googlesource.com/882219
Commit-Queue: Greg Kerr <kerrnel@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533467}
[modify] https://crrev.com/51462da1bd4a72aeebe0cff5bfb7038cf0310114/content/browser/child_process_launcher_helper_mac.cc
[modify] https://crrev.com/51462da1bd4a72aeebe0cff5bfb7038cf0310114/content/browser/sandbox_parameters_mac.h
[modify] https://crrev.com/51462da1bd4a72aeebe0cff5bfb7038cf0310114/content/browser/sandbox_parameters_mac.mm
[modify] https://crrev.com/51462da1bd4a72aeebe0cff5bfb7038cf0310114/services/service_manager/sandbox/mac/ppapi_v2.sb