Coalesce Microsoft Contributors in AUTHORS File

Coalesce all of the individual contributors from Microsoft in AUTHORS file into *@microsoft.com.

Change-Id: Ic0e7e01e8055b426c86fee2a5af2174f071c872a
Reviewed-on: https://chromium-review.googlesource.com/c/1385504Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Rafael Cintron <rafael.cintron@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#58382}

AUTHORS

@@ -15,6 +15,7 @@ NVIDIA Corporation <*@nvidia.com>
 BlackBerry Limited <*@blackberry.com>
 Opera Software ASA <*@opera.com>
 Intel Corporation <*@intel.com>
+Microsoft <*@microsoft.com>
 MIPS Technologies, Inc. <*@mips.com>
 Imagination Technologies, LLC <*@imgtec.com>
 Wave Computing, Inc. <*@wavecomp.com>
@@ -159,7 +160,6 @@ Teddy Katz <teddy.katz@gmail.com>
 Tiancheng "Timothy" Gu <timothygu99@gmail.com>
 Tobias Burnus <burnus@net-b.de>
 Tobias Nießen <tniessen@tnie.de>
-Tom Tan <Tom.Tan@microsoft.com>
 Ujjwal Sharma <usharma1998@gmail.com>
 Victor Costan <costan@gmail.com>
 Vlad Burlik <vladbph@gmail.com>