Have DM manually encode its .png outputs.

Have DM manually encode its .png outputs.

This eliminates some variability on various axes: different PNG encoders, different libpng versions, different formats (RGB, indexed), different unpremultiplication, different sRGB tags.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/3cc0dfffb70c0bd08ed8899efcd2e98da86a6ec7

CQ_EXTRA_TRYBOTS=client.skia:Test-Win8-MSVC-ShuttleB-CPU-AVX2-x86_64-Debug-Trybot

Committed: https://skia.googlesource.com/skia/+/a5114d7f26524f75b96e63ffd796d44749b6248c

[mtklein_C, 2015-08-18 18:31:21]

mtklein@chromium.org changed reviewers:
+ msarett@google.com, stephana@google.com

[mtklein_C, 2015-08-18 18:31:24]

The CQ bit was checked by mtklein@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-18 18:31:34]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1304443002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1304443002/20001

[msarett, 2015-08-18 18:42:56]

This looks great to me!

lgtm

[commit-bot: I haz the power, 2015-08-18 18:42:57]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-18 18:42:58]

Dry run: This issue passed the CQ dry run.

[stephana, 2015-08-18 19:46:34]

On 2015/08/18 18:42:58, commit-bot: I haz the power wrote:
> Dry run: This issue passed the CQ dry run.

lgtm

[mtklein, 2015-08-18 19:48:36]

On 2015/08/18 19:46:34, stephana wrote:
> On 2015/08/18 18:42:58, commit-bot: I haz the power wrote:
> > Dry run: This issue passed the CQ dry run.
> 
> lgtm

Will land this tomorrow morning if all looks calm.

[mtklein_C, 2015-08-19 14:37:02]

The CQ bit was checked by mtklein@chromium.org

[commit-bot: I haz the power, 2015-08-19 14:37:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1304443002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1304443002/20001

[commit-bot: I haz the power, 2015-08-19 14:37:53]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/3cc0dfffb70c0bd08ed8899efcd2e98da86a6ec7

[mtklein_C, 2015-08-19 15:11:20]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1297383002/ by mtklein@chromium.org.

The reason for reverting is: derek +
Test-Win8-MSVC-ShuttleB-CPU-AVX2-x86_64-Debug.

[mtklein_C, 2015-08-19 19:36:15]

The CQ bit was checked by mtklein@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-19 19:36:26]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1304443002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1304443002/40001

[commit-bot: I haz the power, 2015-08-19 20:03:56]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-19 20:03:57]

Dry run: Try jobs failed on following builders:
  Test-Win8-MSVC-ShuttleB-CPU-AVX2-x86_64-Debug-Trybot on client.skia
(JOB_FAILED,
http://build.chromium.org/p/client.skia/builders/Test-Win8-MSVC-ShuttleB-CPU-...)

[mtklein_C, 2015-08-19 20:46:58]

The CQ bit was checked by mtklein@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-19 20:47:11]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1304443002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1304443002/60001

[mtklein_C, 2015-08-19 20:55:00]

If the dry run passes, this is probably good to go.  I'm going to be out until
Monday, so I'll wait to land it until then.  If anyone's feeling eager and wants
to take over, please do.

[commit-bot: I haz the power, 2015-08-19 21:09:41]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-19 21:09:42]

Dry run: This issue passed the CQ dry run.

[mtklein_C, 2015-08-24 20:05:59]

The CQ bit was checked by mtklein@chromium.org

[mtklein_C, 2015-08-24 20:06:00]

The patchset sent to the CQ was uploaded after l-g-t-m from msarett@google.com,
stephana@google.com
Link to the patchset: https://codereview.chromium.org/1304443002/#ps60001
(title: "Fixed?")

[commit-bot: I haz the power, 2015-08-24 20:06:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1304443002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1304443002/60001

[commit-bot: I haz the power, 2015-08-24 20:27:06]

Committed patchset #4 (id:60001) as
https://skia.googlesource.com/skia/+/a5114d7f26524f75b96e63ffd796d44749b6248c

[hal.canary, 2015-08-24 20:35:05]

halcanary@google.com changed reviewers:
+ halcanary@google.com

[hal.canary, 2015-08-24 20:35:06]

https://codereview.chromium.org/1304443002/diff/60001/dm/DM.cpp
File dm/DM.cpp (right):

https://codereview.chromium.org/1304443002/diff/60001/dm/DM.cpp#newcode496
dm/DM.cpp:496: bitmap = SkBitmap();
bitmap.reset();