The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f531b41792b7da80de0c50124be040497d91eca8

commit f531b41792b7da80de0c50124be040497d91eca8
Author: hunyadym <hunyadym@chromium.org>
Date: Fri Oct 28 12:40:55 2016

Add "critical" parameter to DMServer requests.
Set value to true if the request is the first policy fetch.

BUG= 660009 

Review-Url: https://codereview.chromium.org/2458653003
Cr-Commit-Position: refs/heads/master@{#428344}

[modify] https://crrev.com/f531b41792b7da80de0c50124be040497d91eca8/components/policy/core/common/cloud/cloud_policy_client.cc
[modify] https://crrev.com/f531b41792b7da80de0c50124be040497d91eca8/components/policy/core/common/cloud/cloud_policy_constants.cc
[modify] https://crrev.com/f531b41792b7da80de0c50124be040497d91eca8/components/policy/core/common/cloud/cloud_policy_constants.h
[modify] https://crrev.com/f531b41792b7da80de0c50124be040497d91eca8/components/policy/core/common/cloud/device_management_service.cc
[modify] https://crrev.com/f531b41792b7da80de0c50124be040497d91eca8/components/policy/core/common/cloud/device_management_service.h
[modify] https://crrev.com/f531b41792b7da80de0c50124be040497d91eca8/components/policy/core/common/cloud/device_management_service_unittest.cc

Verified on R57(9202.4.0;57.0.2987.8), we see the critical=true query string in the initial device policy request:
1) That is made immediately after/as a part of  enrollment.
2) After reboot of a device.

The 'critical' parameter is not set on subsequent device policy requests.

@hunyadym, was wondering if there's a corresponding DM server bug tracking the FR where DM server maybe prioritizes the request if it sees a request with the critical query parameter. Or does the DM server do this by default?

b/31678912 was the original bug.

I don't know about DM server related bugs, maybe Jin can help with that.

DMServer side work is tracked here: b/31505645

Marking this as verified based on the verification details provided in #c5.