Revert "Add a chromium author that could not add himself"

This reverts commit bc08f94f.

Reason for revert: Not needed. There was an issue with the CLA not being accepted.

Original change's description:
> Add a chromium author that could not add himself
> 
> BUG=1116202
> 
> Change-Id: I10738961da81ad153b770210e3d969210b0bcd0f
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2354557
> Commit-Queue: Donn Denman <donnd@chromium.org>
> Commit-Queue: Theresa  <twellington@chromium.org>
> Auto-Submit: Donn Denman <donnd@chromium.org>
> Reviewed-by: Theresa  <twellington@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#797916}

TBR=donnd@chromium.org,twellington@chromium.org

Change-Id: Iaffe8f52f36455ba0c7746b0ed47fa2d9f5db209
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1116202
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2354562Reviewed-by: Donn Denman <donnd@chromium.org>
Commit-Queue: Donn Denman <donnd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797968}

AUTHORS

@@ -721,7 +721,6 @@ Nagarajan Narayanan <nagarajan.n@samsung.com>
 Nagarjuna Atluri <nagarjuna.a@samsung.com>
 Naiem Shaik <naiem.shaik@gmail.com>
 Naoki Takano <takano.naoki@gmail.com>
-Nathan Mitchell <nathaniel.v.mitchell@gmail.com>
 Naveen Bobbili <naveenbobbili@motorola.com>
 Naveen Bobbili <qghc36@motorola.com>
 Naveen Kumar Devaraj <devarajn@amazon.com>