reduce setting wallpaper latency.

reduce setting wallpaper latency.

Previously, setting the wallpaper is slow because
there are multiple decoding / encoding (esp png)
involved. This CL asks ImageDecoder to do a more
general decoding based on the bytes from Arc and
thus, Android does not need to do decoding and
encoding anymore.

Test=Set large wallpaper becomes faster.

Bug=666974
Committed: https://crrev.com/8e4822ebbb9b4108013d9246974b228cb52834f3
Cr-Commit-Position: refs/heads/master@{#433692}

[Muyuan, 2016-11-19 00:22:28]

muyuanli@chromium.org changed reviewers:
+ lhchavez@chromium.org

[Luis Héctor Chávez, 2016-11-21 17:22:51]

lhchavez@chromium.org changed reviewers:
+ dcheng@chromium.org

[Luis Héctor Chávez, 2016-11-21 17:22:52]

lgtm

(adding dcheng@ for the .mojom change)

[dcheng, 2016-11-21 22:22:36]

rs lgtm

[Muyuan, 2016-11-21 22:38:03]

The CQ bit was checked by muyuanli@chromium.org

[commit-bot: I haz the power, 2016-11-21 22:38:57]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-21 23:31:17]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1479767883253720, "parent_rev":
"02872e7ecf7610780be8892b4db4c468b7406f10", "commit_rev":
"960088a9b794210a0a30988023abf1a9a689e7df"}

[commit-bot: I haz the power, 2016-11-21 23:33:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-21 23:38:41]

Description was changed from

==========
reduce setting wallpaper latency.

Previously, setting the wallpaper is slow because
there are multiple decoding / encoding (esp png)
involved. This CL asks ImageDecoder to do a more
general decoding based on the bytes from Arc and
thus, Android does not need to do decoding and
encoding anymore.

Test=Set large wallpaper becomes faster.

Bug=666974
==========

to

==========
reduce setting wallpaper latency.

Previously, setting the wallpaper is slow because
there are multiple decoding / encoding (esp png)
involved. This CL asks ImageDecoder to do a more
general decoding based on the bytes from Arc and
thus, Android does not need to do decoding and
encoding anymore.

Test=Set large wallpaper becomes faster.

Bug=666974

Committed: https://crrev.com/8e4822ebbb9b4108013d9246974b228cb52834f3
Cr-Commit-Position: refs/heads/master@{#433692}
==========

[commit-bot: I haz the power, 2016-11-21 23:38:43]

Patchset 1 (id:??) landed as
https://crrev.com/8e4822ebbb9b4108013d9246974b228cb52834f3
Cr-Commit-Position: refs/heads/master@{#433692}