The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/43112301e2844a6d33bb84f575256d5097e8d9a9

commit 43112301e2844a6d33bb84f575256d5097e8d9a9
Author: Wenzhao Zang <wzang@chromium.org>
Date: Thu Jun 14 22:00:06 2018

cros: Change wallpaper decoding format to default

This issue did not show up earlier because the old wallpaper picker
only contained jpeg images.

Also changes |shrink_to_fit| to true.

Bug:  852844 
Change-Id: Ia26a091ee38a6de43454eda0243ff24386e77da8
Reviewed-on: https://chromium-review.googlesource.com/1101400
Reviewed-by: Weidong Guo <weidongg@chromium.org>
Commit-Queue: Wenzhao (Colin) Zang <wzang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567435}
[modify] https://crrev.com/43112301e2844a6d33bb84f575256d5097e8d9a9/ash/wallpaper/wallpaper_utils/wallpaper_decoder.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/eef973b148054f5c383ad73d9c0d5314d4e834a1

commit eef973b148054f5c383ad73d9c0d5314d4e834a1
Author: Wenzhao (Colin) Zang <wzang@chromium.org>
Date: Wed Jun 27 19:42:54 2018

Revert "cros: Change wallpaper decoding format to default"

This reverts commit 43112301e2844a6d33bb84f575256d5097e8d9a9.

Reason for revert: There's occasional decoding failure on login screen.
Will have to revert this CL first and find a better fix for the original bug.

Original change's description:
> cros: Change wallpaper decoding format to default
> 
> This issue did not show up earlier because the old wallpaper picker
> only contained jpeg images.
> 
> Also changes |shrink_to_fit| to true.
> 
> Bug:  852844 
> Change-Id: Ia26a091ee38a6de43454eda0243ff24386e77da8
> Reviewed-on: https://chromium-review.googlesource.com/1101400
> Reviewed-by: Weidong Guo <weidongg@chromium.org>
> Commit-Queue: Wenzhao (Colin) Zang <wzang@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#567435}

TBR=wzang@chromium.org,weidongg@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug:  852844 
Change-Id: Iede6a0c39b14ea7a69f980ea6d47d39628ba31ac
Reviewed-on: https://chromium-review.googlesource.com/1117398
Reviewed-by: Wenzhao (Colin) Zang <wzang@chromium.org>
Commit-Queue: Wenzhao (Colin) Zang <wzang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570866}
[modify] https://crrev.com/eef973b148054f5c383ad73d9c0d5314d4e834a1/ash/wallpaper/wallpaper_utils/wallpaper_decoder.cc