The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7a3b1574bb3a12078de8008771103163e0317652

commit 7a3b1574bb3a12078de8008771103163e0317652
Author: KongQun Yang <kqyang@chromium.org>
Date: Tue Jun 06 18:38:10 2017

Enable VP9 in MP4 by default

Removed command line switch --enable-vp9-in-mp4.

Bug:  726759 
Change-Id: Ie6bf267ec69536a1ccbe00f558aa9fe0ebb50dde
Reviewed-on: https://chromium-review.googlesource.com/511165
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Commit-Queue: Kongqun Yang <kqyang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#477349}
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/chrome/browser/media/encrypted_media_browsertest.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/chrome/browser/media/encrypted_media_supported_types_browsertest.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/content/browser/media/media_browsertest.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/content/browser/media/media_canplaytype_browsertest.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/content/browser/media/media_capabilities_browsertest.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/content/browser/renderer_host/render_process_host_impl.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/media/base/media_switches.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/media/base/media_switches.h
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/media/base/mime_util_internal.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/media/filters/chunk_demuxer_unittest.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/media/filters/stream_parser_factory.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/media/formats/mp4/box_definitions.cc
[modify] https://crrev.com/7a3b1574bb3a12078de8008771103163e0317652/media/test/pipeline_integration_test.cc

Your change meets the bar and is auto-approved for M60. Please go ahead and merge the CL to branch 3112 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), josafat@(ChromeOS), bustamante@(Desktop)

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

Please merge the patch to M60 branch(3112),Beta RC cut is scheduled @ 4.00 PM PST today(06/07).

Looks like I don't have permission to land directly. I've created a CL for review: https://chromium-review.googlesource.com/c/527672/

Or Chris/Xiaohan, do you mind running the below command and land it for me:

gclient sync --with_branch_heads
git drover --branch 3112 --cherry-pick 7a3b1574bb3a12078de8008771103163e0317652

Sure, I'll do it

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e

commit 1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e
Author: Chris Cunningham <chcunningham@chromium.org>
Date: Wed Jun 07 22:31:19 2017

Enable VP9 in MP4 by default

Removed command line switch --enable-vp9-in-mp4.

Bug:  726759 
Change-Id: Ie6bf267ec69536a1ccbe00f558aa9fe0ebb50dde
Reviewed-on: https://chromium-review.googlesource.com/511165
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Commit-Queue: Kongqun Yang <kqyang@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#477349}
Review-Url: https://codereview.chromium.org/2928873002 .
Cr-Commit-Position: refs/branch-heads/3112@{#239}
Cr-Branched-From: b6460e24cf59f429d69de255538d0fc7a425ccf9-refs/heads/master@{#474897}

[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/chrome/browser/media/encrypted_media_browsertest.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/chrome/browser/media/encrypted_media_supported_types_browsertest.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/content/browser/media/media_browsertest.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/content/browser/media/media_canplaytype_browsertest.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/content/browser/media/media_capabilities_browsertest.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/content/browser/renderer_host/render_process_host_impl.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/media/base/media_switches.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/media/base/media_switches.h
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/media/base/mime_util_internal.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/media/filters/chunk_demuxer_unittest.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/media/filters/stream_parser_factory.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/media/formats/mp4/box_definitions.cc
[modify] https://crrev.com/1f1ddcecbf7c77407034739ed5371dcd7dfc8c2e/media/test/pipeline_integration_test.cc