Add stable id to PaintImage.

Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2873003002
Cr-Original-Commit-Position: refs/heads/master@{#471351}
Committed: https://chromium.googlesource.com/chromium/src/+/ae192fde12e7fba4ac2d8f027037d10c3d0f22a4
Review-Url: https://codereview.chromium.org/2873003002
Cr-Commit-Position: refs/heads/master@{#472182}
Committed: https://chromium.googlesource.com/chromium/src/+/81a39a3185a65ddf4b517b7c389cce6d19a8249f

[vmpstr, 2017-05-09 20:31:32]

Description was changed from

==========
Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
==========

to

==========
Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel
==========

[vmpstr, 2017-05-09 20:31:57]

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

[vmpstr, 2017-05-09 20:32:50]

Please take a look.

[commit-bot: I haz the power, 2017-05-09 20:34:23]

Dry run: 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, 2017-05-09 20:40:02]

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

[commit-bot: I haz the power, 2017-05-09 20:40:03]

Dry run: Try jobs failed on following builders:
  android_arm64_dbg_recipe on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_arm6...)
  android_clang_dbg_recipe on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_clan...)
  android_compile_dbg on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_comp...)
  android_cronet on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_cron...)
  android_n5x_swarming_rel on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_n5x_...)
  cast_shell_android on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/cast_shell_a...)

[vmpstr, 2017-05-09 22:50:22]

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

[commit-bot: I haz the power, 2017-05-09 22:51:42]

Dry run: CQ is trying da patch.

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

[Khushal, 2017-05-09 22:57:21]

lgtm.

https://codereview.chromium.org/2873003002/diff/1/cc/paint/paint_image.h
File cc/paint/paint_image.h (right):

https://codereview.chromium.org/2873003002/diff/1/cc/paint/paint_image.h#newc...
cc/paint/paint_image.h:54: static base::AtomicSequenceNumber s_next_id_;
Do you need to declare this again in the .cc file?

https://codereview.chromium.org/2873003002/diff/1/cc/paint/paint_image.h#newc...
cc/paint/paint_image.h:56: Id stable_id_;
nit: Just id_ should be good enough.

[commit-bot: I haz the power, 2017-05-09 23:38:38]

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

[commit-bot: I haz the power, 2017-05-09 23:38:39]

Dry run: Try jobs failed on following builders:
  android_n5x_swarming_rel on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_n5x_...)

[vmpstr, 2017-05-09 23:40:46]

vmpstr@chromium.org changed reviewers:
+ chcunningham@chromium.org, chrishtr@chromium.org, piman@chromium.org

[vmpstr, 2017-05-09 23:40:46]

+piman for content/
+chcunningham for media/
+chrishtr for blink.

Please take a look.

[vmpstr, 2017-05-09 23:41:34]

On 2017/05/09 22:57:21, Khushal wrote:
> lgtm.
> 
> https://codereview.chromium.org/2873003002/diff/1/cc/paint/paint_image.h
> File cc/paint/paint_image.h (right):
> 
>
https://codereview.chromium.org/2873003002/diff/1/cc/paint/paint_image.h#newc...
> cc/paint/paint_image.h:54: static base::AtomicSequenceNumber s_next_id_;
> Do you need to declare this again in the .cc file?

This is typically required... There are other examples of this in the codebase.

> 
>
https://codereview.chromium.org/2873003002/diff/1/cc/paint/paint_image.h#newc...
> cc/paint/paint_image.h:56: Id stable_id_;
> nit: Just id_ should be good enough.

Will change.

[piman, 2017-05-09 23:44:25]

lgtm

[chcunningham, 2017-05-10 20:10:31]

media lgtm

[vmpstr, 2017-05-10 22:12:11]

ping for blink review

[chrishtr, 2017-05-10 22:56:11]

https://codereview.chromium.org/2873003002/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/graphics/Image.cpp (right):

https://codereview.chromium.org/2873003002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/graphics/Image.cpp:57:
stable_image_id_(PaintImage::GetNextId()) {}
How about making Image the class which creates its own id,
instead of delegating to PaintImage?

[vmpstr, 2017-05-10 23:21:47]

https://codereview.chromium.org/2873003002/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/graphics/Image.cpp (right):

https://codereview.chromium.org/2873003002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/graphics/Image.cpp:57:
stable_image_id_(PaintImage::GetNextId()) {}
On 2017/05/10 22:56:11, chrishtr wrote:
> How about making Image the class which creates its own id,
> instead of delegating to PaintImage?

Hm.. You mean have the id generation happen from Image? This id needs to be
unique for any paint image created (unless of course it explicitly references
the same logical image). I'm not sure how to guarantee that without actually
asking PaintImage to get the next id... This is kind of like an Image that
creates its own id, except it just uses PaintImage as the generator.

Do you have a specific concern about this breaking something?

[chrishtr, 2017-05-10 23:28:23]

On 2017/05/10 at 23:21:47, vmpstr wrote:
>
https://codereview.chromium.org/2873003002/diff/40001/third_party/WebKit/Sour...
> File third_party/WebKit/Source/platform/graphics/Image.cpp (right):
> 
>
https://codereview.chromium.org/2873003002/diff/40001/third_party/WebKit/Sour...
> third_party/WebKit/Source/platform/graphics/Image.cpp:57:
stable_image_id_(PaintImage::GetNextId()) {}
> On 2017/05/10 22:56:11, chrishtr wrote:
> > How about making Image the class which creates its own id,
> > instead of delegating to PaintImage?
> 
> Hm.. You mean have the id generation happen from Image? This id needs to be
unique for any paint image created (unless of course it explicitly references
the same logical image). I'm not sure how to guarantee that without actually
asking PaintImage to get the next id... This is kind of like an Image that
creates its own id, except it just uses PaintImage as the generator.
> 
> Do you have a specific concern about this breaking something?

Not breaking something, just that it makes the code a bit simpler. Are you
concerned about a single Image using multiple PaintImages?

[vmpstr, 2017-05-10 23:32:29]

On 2017/05/10 23:28:23, chrishtr wrote:
> On 2017/05/10 at 23:21:47, vmpstr wrote:
> >
>
https://codereview.chromium.org/2873003002/diff/40001/third_party/WebKit/Sour...
> > File third_party/WebKit/Source/platform/graphics/Image.cpp (right):
> > 
> >
>
https://codereview.chromium.org/2873003002/diff/40001/third_party/WebKit/Sour...
> > third_party/WebKit/Source/platform/graphics/Image.cpp:57:
> stable_image_id_(PaintImage::GetNextId()) {}
> > On 2017/05/10 22:56:11, chrishtr wrote:
> > > How about making Image the class which creates its own id,
> > > instead of delegating to PaintImage?
> > 
> > Hm.. You mean have the id generation happen from Image? This id needs to be
> unique for any paint image created (unless of course it explicitly references
> the same logical image). I'm not sure how to guarantee that without actually
> asking PaintImage to get the next id... This is kind of like an Image that
> creates its own id, except it just uses PaintImage as the generator.
> > 
> > Do you have a specific concern about this breaking something?
> 
> Not breaking something, just that it makes the code a bit simpler. Are you
> concerned about a single Image using multiple PaintImages?

Yeah the intent of this id is to avoid this exact case. We don't want multiple
SkImages/PaintImages produced by one Image to have different ids, since this
would be used to determine the eligibility for checker imaging. So if a new id
appears, we might decide to checker the image although (partial) contents of
that image were already on screen which would cause a flicker.

[chrishtr, 2017-05-10 23:41:53]

lgtm

[vmpstr, 2017-05-10 23:42:21]

The CQ bit was checked by vmpstr@chromium.org

[vmpstr, 2017-05-10 23:42:21]

The patchset sent to the CQ was uploaded after l-g-t-m from
khushalsagar@chromium.org, piman@chromium.org
Link to the patchset: https://codereview.chromium.org/2873003002/#ps40001
(title: "update")

[commit-bot: I haz the power, 2017-05-10 23:43:47]

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, 2017-05-11 01:00:24]

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

[commit-bot: I haz the power, 2017-05-11 01:00:28]

Try jobs failed on following builders:
  linux_chromium_asan_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[vmpstr, 2017-05-11 14:43:41]

The CQ bit was checked by vmpstr@chromium.org

[commit-bot: I haz the power, 2017-05-11 14:44:13]

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, 2017-05-11 17:16:00]

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

[commit-bot: I haz the power, 2017-05-11 17:16:02]

Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[vmpstr, 2017-05-11 17:20:12]

The CQ bit was checked by vmpstr@chromium.org

[commit-bot: I haz the power, 2017-05-11 17:20:48]

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, 2017-05-11 19:57:21]

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

[commit-bot: I haz the power, 2017-05-11 19:57:23]

Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[vmpstr, 2017-05-12 15:27:13]

The CQ bit was checked by vmpstr@chromium.org

[commit-bot: I haz the power, 2017-05-12 15:27:46]

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, 2017-05-12 17:36:04]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1494602833599230,
"parent_rev": "036a8648e3fee70b4414d0567fdf278ece77ce8b", "commit_rev":
"ae192fde12e7fba4ac2d8f027037d10c3d0f22a4"}

[commit-bot: I haz the power, 2017-05-12 17:36:16]

Description was changed from

==========
Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel
==========

to

==========
Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2873003002
Cr-Commit-Position: refs/heads/master@{#471351}
Committed:
https://chromium.googlesource.com/chromium/src/+/ae192fde12e7fba4ac2d8f027037...
==========

[commit-bot: I haz the power, 2017-05-12 17:36:18]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/ae192fde12e7fba4ac2d8f027037...

[Justin Donnelly, 2017-05-12 18:44:40]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/2880813002/ by jdonnelly@chromium.org.

The reason for reverting is: This change introduced a static initializer:
PaintImage::s_next_id_.

See resulting failure at:
https://uberchromegw.corp.google.com/i/chromium/builders/Linux%20x64/builds/3....

[piman, 2017-05-12 19:02:58]

https://codereview.chromium.org/2873003002/diff/40001/cc/paint/paint_image.h
File cc/paint/paint_image.h (right):

https://codereview.chromium.org/2873003002/diff/40001/cc/paint/paint_image.h#...
cc/paint/paint_image.h:54: static base::AtomicSequenceNumber s_next_id_;
Use base::StaticAtomicSequenceNumber instead

[vmpstr, 2017-05-12 19:45:28]

Description was changed from

==========
Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2873003002
Cr-Commit-Position: refs/heads/master@{#471351}
Committed:
https://chromium.googlesource.com/chromium/src/+/ae192fde12e7fba4ac2d8f027037...
==========

to

==========
Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2873003002
Cr-Commit-Position: refs/heads/master@{#471351}
Committed:
https://chromium.googlesource.com/chromium/src/+/ae192fde12e7fba4ac2d8f027037...
==========

[vmpstr, 2017-05-12 20:01:39]

My bad. I've updated it to use StaticAtomicSequenceNumber. piman@ do you mind
taking a quick look?

[piman, 2017-05-12 20:11:29]

lgtm

[vmpstr, 2017-05-12 20:12:32]

The CQ bit was checked by vmpstr@chromium.org

[vmpstr, 2017-05-12 20:12:33]

The patchset sent to the CQ was uploaded after l-g-t-m from
chcunningham@chromium.org, chrishtr@chromium.org, khushalsagar@chromium.org
Link to the patchset: https://codereview.chromium.org/2873003002/#ps60001
(title: "staticatomicsequencenumber")

[commit-bot: I haz the power, 2017-05-12 20:13:22]

CQ is trying da patch.

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

[findit-for-me, 2017-05-12 22:18:41]

Findit (https://goo.gl/kROfz5) identified this CL at revision 471351 as the
culprit for
failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3Itb...

[vmpstr, 2017-05-12 22:24:15]

The CQ bit was unchecked by vmpstr@chromium.org

[vmpstr, 2017-05-12 22:30:49]

The CQ bit was checked by vmpstr@chromium.org

[vmpstr, 2017-05-12 22:30:49]

The patchset sent to the CQ was uploaded after l-g-t-m from
chcunningham@chromium.org, chrishtr@chromium.org, khushalsagar@chromium.org,
piman@chromium.org
Link to the patchset: https://codereview.chromium.org/2873003002/#ps80001
(title: "initializeid")

[commit-bot: I haz the power, 2017-05-12 22:31:55]

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, 2017-05-13 01:03:05]

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

[commit-bot: I haz the power, 2017-05-13 01:03:07]

Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[vmpstr, 2017-05-15 14:57:46]

The CQ bit was checked by vmpstr@chromium.org

[commit-bot: I haz the power, 2017-05-15 14:58:24]

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, 2017-05-15 16:34:43]

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

[commit-bot: I haz the power, 2017-05-15 16:34:45]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[vmpstr, 2017-05-15 19:36:01]

The CQ bit was checked by vmpstr@chromium.org

[commit-bot: I haz the power, 2017-05-15 19:36:41]

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, 2017-05-15 21:23:08]

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

[commit-bot: I haz the power, 2017-05-15 21:23:09]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[vmpstr, 2017-05-16 15:01:24]

The CQ bit was checked by vmpstr@chromium.org

[commit-bot: I haz the power, 2017-05-16 15:02:30]

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, 2017-05-16 16:20:39]

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

[commit-bot: I haz the power, 2017-05-16 16:20:41]

Try jobs failed on following builders:
  win_chromium_compile_dbg_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_comp...)

[vmpstr, 2017-05-16 16:56:23]

The CQ bit was checked by vmpstr@chromium.org

[vmpstr, 2017-05-16 16:56:23]

The patchset sent to the CQ was uploaded after l-g-t-m from
chcunningham@chromium.org, chrishtr@chromium.org, khushalsagar@chromium.org,
piman@chromium.org
Link to the patchset: https://codereview.chromium.org/2873003002/#ps100001
(title: "rebase")

[commit-bot: I haz the power, 2017-05-16 16:57:26]

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, 2017-05-16 19:30:24]

CQ is committing da patch.

Bot data: {"patchset_id": 100001, "attempt_start_ts": 1494953783391440,
"parent_rev": "6ceca38dd2d95271e9fbce453e26b651e57631a0", "commit_rev":
"81a39a3185a65ddf4b517b7c389cce6d19a8249f"}

[commit-bot: I haz the power, 2017-05-16 19:30:32]

Description was changed from

==========
Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2873003002
Cr-Commit-Position: refs/heads/master@{#471351}
Committed:
https://chromium.googlesource.com/chromium/src/+/ae192fde12e7fba4ac2d8f027037...
==========

to

==========
Add stable id to PaintImage.

This patch adds a stable id into PaintImage. This is stable in the sense
that if the blink::Image that generated the paint image hasn't changed,
then the id would be the same. It's used in a case where either we have
a partially loaded image that finishes loading or an animated image
ticks to a new frame. In those cases, the SkImage unique id is different
since the contents of the image are different. However, the stable id
should remain the same to indicate that it's a part of logically the
same image.

The primary use for the stable id would be to determine whether the
compositor is allowed to checker the image. Specifically, if we have
ever displayed an image stable id X, then all other images with the
same stable id X are not allowed to be checker imaged.

R=khushalsagar@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2873003002
Cr-Original-Commit-Position: refs/heads/master@{#471351}
Committed:
https://chromium.googlesource.com/chromium/src/+/ae192fde12e7fba4ac2d8f027037...
Review-Url: https://codereview.chromium.org/2873003002
Cr-Commit-Position: refs/heads/master@{#472182}
Committed:
https://chromium.googlesource.com/chromium/src/+/81a39a3185a65ddf4b517b7c389c...
==========

[commit-bot: I haz the power, 2017-05-16 19:30:34]

Committed patchset #6 (id:100001) as
https://chromium.googlesource.com/chromium/src/+/81a39a3185a65ddf4b517b7c389c...