Use scrollOrigin instead of minimumScrollPosition to calculate position.

Use scrollOrigin instead of minimumScrollPosition to calculate current
layer position in PaintLayerCompositor and GraphicsLayer.

It makes more sense to use the area's scrollOrigin() instead of the
minimumScrollPosition(), as the minimumScrollPosition may be
overridden by users of the area (see e.g.
https://codereview.chromium.org/2096633002/).

BUG=625084
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/0ace38cb311d604745708c31284ba4ff291c4734
Cr-Commit-Position: refs/heads/master@{#421159}

[Eric Seckler, 2016-07-20 14:30:10]

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

[commit-bot: I haz the power, 2016-07-20 14:30:28]

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, 2016-07-20 15:52:26]

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

[commit-bot: I haz the power, 2016-07-20 15:52:27]

Dry run: This issue passed the CQ dry run.

[Eric Seckler, 2016-07-20 15:56:49]

Description was changed from

==========
Use scrollOrigin instead of minimumScrollPosition to calculate offset.

Use scrollOrigin instead of minimumScrollPosition to calculate current
offset position in PaintLayerCompositor and GraphicsLayer.

BUG=625084
==========

to

==========
Use scrollOrigin instead of minimumScrollPosition to calculate offset.

Use scrollOrigin instead of minimumScrollPosition to calculate current
offset position in PaintLayerCompositor and GraphicsLayer.

It makes more sense to use the area's scrollOrigin() instead of the
minimumScrollPosition(), as the minimumScrollPosition may be
overridden by users of the area (see e.g.
https://codereview.chromium.org/2096633002/).

BUG=625084
==========

[Eric Seckler, 2016-07-20 16:18:50]

eseckler@chromium.org changed reviewers:
+ bokan@chromium.org

[Eric Seckler, 2016-07-20 16:18:50]

Hi David,

Looks like changing to scrollOrigin doesn't break anything here.

With regards to blink::Scrollbar, which also uses min/max pos, it seems that it
sets positions correctly according to
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/scrol...
(essentially scaling the thumb position between min and max). I'm not sure if it
takes min/max into account for sizing/positioning the thumb, though. Not sure if
we need to change anything there (.. or what our intended behavior would be in
the context of overridden min/max).

Thanks!
Eric

[Eric Seckler, 2016-07-21 10:01:48]

Description was changed from

==========
Use scrollOrigin instead of minimumScrollPosition to calculate offset.

Use scrollOrigin instead of minimumScrollPosition to calculate current
offset position in PaintLayerCompositor and GraphicsLayer.

It makes more sense to use the area's scrollOrigin() instead of the
minimumScrollPosition(), as the minimumScrollPosition may be
overridden by users of the area (see e.g.
https://codereview.chromium.org/2096633002/).

BUG=625084
==========

to

==========
Use scrollOrigin instead of minimumScrollPosition to calculate current
layer position in PaintLayerCompositor and GraphicsLayer.

It makes more sense to use the area's scrollOrigin() instead of the
minimumScrollPosition(), as the minimumScrollPosition may be
overridden by users of the area (see e.g.
https://codereview.chromium.org/2096633002/).

BUG=625084
==========

[bokan, 2016-07-22 02:12:35]

this is lgtm, we can look at scrollbars if we need to later.

[Eric Seckler, 2016-07-22 08:20:54]

eseckler@chromium.org changed reviewers:
+ schenney@chromium.org

[Eric Seckler, 2016-07-22 08:20:55]

+schenney@ for platform/

[Eric Seckler, 2016-09-22 13:51:42]

While this is not blocking anything anymore (we went with a different approach
for screenshotting that doesn't override minimumScrollPosition), should we still
land this anyway for consistency with
ScrollingCoordinator::scrollableAreaScrollLayerDidChange() ?

[Sami, 2016-09-22 14:35:24]

On 2016/09/22 13:51:42, Eric Seckler wrote:
> While this is not blocking anything anymore (we went with a different approach
> for screenshotting that doesn't override minimumScrollPosition), should we
still
> land this anyway for consistency with
> ScrollingCoordinator::scrollableAreaScrollLayerDidChange() ?

Seems good for consistency I think.

[bokan, 2016-09-22 14:38:11]

Yup, sgtm

[Eric Seckler, 2016-09-23 09:28:11]

Stephen, can you have a quick look at the GraphicsLayer change for owner
approval? Thanks!

[Stephen Chennney, 2016-09-26 13:16:31]

On 2016/09/23 09:28:11, Eric Seckler wrote:
> Stephen, can you have a quick look at the GraphicsLayer change for owner
> approval? Thanks!

LGTM. Makes sense to me.

[Eric Seckler, 2016-09-26 13:17:30]

The CQ bit was checked by eseckler@chromium.org

[commit-bot: I haz the power, 2016-09-26 13:17:39]

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, 2016-09-26 14:24:34]

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

[commit-bot: I haz the power, 2016-09-26 14:24:36]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Eric Seckler, 2016-09-26 14:57:30]

The CQ bit was checked by eseckler@chromium.org

[commit-bot: I haz the power, 2016-09-26 14:57:54]

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, 2016-09-26 16:15:39]

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

[commit-bot: I haz the power, 2016-09-26 16:15:40]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Eric Seckler, 2016-09-26 16:30:20]

The CQ bit was checked by eseckler@chromium.org

[commit-bot: I haz the power, 2016-09-26 16:30:49]

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, 2016-09-26 17:57:46]

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

[commit-bot: I haz the power, 2016-09-26 17:57:48]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Eric Seckler, 2016-09-27 08:17:15]

Description was changed from

==========
Use scrollOrigin instead of minimumScrollPosition to calculate current
layer position in PaintLayerCompositor and GraphicsLayer.

It makes more sense to use the area's scrollOrigin() instead of the
minimumScrollPosition(), as the minimumScrollPosition may be
overridden by users of the area (see e.g.
https://codereview.chromium.org/2096633002/).

BUG=625084
==========

to

==========
Use scrollOrigin instead of minimumScrollPosition to calculate current
layer position in PaintLayerCompositor and GraphicsLayer.

It makes more sense to use the area's scrollOrigin() instead of the
minimumScrollPosition(), as the minimumScrollPosition may be
overridden by users of the area (see e.g.
https://codereview.chromium.org/2096633002/).

BUG=625084
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[Eric Seckler, 2016-09-27 08:17:43]

The CQ bit was checked by eseckler@chromium.org

[Eric Seckler, 2016-09-27 08:17:43]

The patchset sent to the CQ was uploaded after l-g-t-m from bokan@chromium.org,
schenney@chromium.org
Link to the patchset: https://codereview.chromium.org/2169483002/#ps20001
(title: "rebase.")

[commit-bot: I haz the power, 2016-09-27 08:17:53]

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, 2016-09-27 09:39:39]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-27 09:41:33]

Description was changed from

==========
Use scrollOrigin instead of minimumScrollPosition to calculate current
layer position in PaintLayerCompositor and GraphicsLayer.

It makes more sense to use the area's scrollOrigin() instead of the
minimumScrollPosition(), as the minimumScrollPosition may be
overridden by users of the area (see e.g.
https://codereview.chromium.org/2096633002/).

BUG=625084
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Use scrollOrigin instead of minimumScrollPosition to calculate current
layer position in PaintLayerCompositor and GraphicsLayer.

It makes more sense to use the area's scrollOrigin() instead of the
minimumScrollPosition(), as the minimumScrollPosition may be
overridden by users of the area (see e.g.
https://codereview.chromium.org/2096633002/).

BUG=625084
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/0ace38cb311d604745708c31284ba4ff291c4734
Cr-Commit-Position: refs/heads/master@{#421159}
==========

[commit-bot: I haz the power, 2016-09-27 09:41:35]

Patchset 2 (id:??) landed as
https://crrev.com/0ace38cb311d604745708c31284ba4ff291c4734
Cr-Commit-Position: refs/heads/master@{#421159}