cc: Scroll on main when possible incorrect hit testing hits scrollbar.

cc: Scroll on main when possible incorrect hit testing hits scrollbar.

As explained in crrev.com/238803005, it is possible that the composited
layers have holes, if the point hits the first layer below the viewport
point and the scrollbar layer, and the scrollbar layer is not an ancestor
of the former layer, we should scroll on main, as shown below:

1) Should scroll on main:

+--.....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+--....
+----....composited_unscrollable_layer (<-viewport point hits this)

2) Can scroll on impl:
+--....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+----....composited_unscrollable_layer (<-viewport point hits this)

BUG=601342
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Committed: https://crrev.com/0b34eb5f70ea985690e856d6f58284835e629c75
Cr-Commit-Position: refs/heads/master@{#386880}

[sunxd, 2016-04-12 18:17:01]

Description was changed from

==========
cc: Scroll on main when possible incorrect hit testing hits scrollbar.

As explained in crrev.com/238803005, it is possible that the composited
layers have holes, if the point hits the first layer below the viewport
point and the scrollbar layer, and the scrollbar layer is not an ancestor
of the former layer, we should scroll on main, as shown below:

1) Should scroll on main:

+--.....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+--....
+----....composited_unscrollable_layer (<-viewport point hits this)

2) Can scroll on impl:
+--....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+----....composited_unscrollable_layer (<-viewport point hits this)

BUG=601342
==========

to

==========
cc: Scroll on main when possible incorrect hit testing hits scrollbar.

As explained in crrev.com/238803005, it is possible that the composited
layers have holes, if the point hits the first layer below the viewport
point and the scrollbar layer, and the scrollbar layer is not an ancestor
of the former layer, we should scroll on main, as shown below:

1) Should scroll on main:

+--.....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+--....
+----....composited_unscrollable_layer (<-viewport point hits this)

2) Can scroll on impl:
+--....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+----....composited_unscrollable_layer (<-viewport point hits this)

BUG=601342
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
==========

[sunxd, 2016-04-12 18:40:55]

sunxd@chromium.org changed reviewers:
+ ajuma@chromium.org, dtapuska@chromium.org, vollick@chromium.org

[sunxd, 2016-04-12 18:40:56]

The function name seems too long, I need some suggestions.

[Ian Vollick, 2016-04-12 18:55:28]

On 2016/04/12 18:40:56, sunxd wrote:
> The function name seems too long, I need some suggestions.

I don't mind the long name; it's pretty clear what it does.

lgtm, though Ali, could you PTAL, too?

[sunxd, 2016-04-12 20:05:40]

The unit tests used to pass even without the patch, because the scrollable layer
fully covers the scrollbar layer.

[Ian Vollick, 2016-04-12 20:41:10]

On 2016/04/12 20:05:40, sunxd wrote:
> The unit tests used to pass even without the patch, because the scrollable
layer
> fully covers the scrollbar layer.

Gotcha :) Still lgtm.

[ajuma, 2016-04-12 21:31:55]

lgtm too

[sunxd, 2016-04-13 00:17:43]

The CQ bit was checked by sunxd@chromium.org

[commit-bot: I haz the power, 2016-04-13 00:18:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1878323002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1878323002/20001

[dtapuska, 2016-04-13 01:03:11]

On 2016/04/12 21:31:55, ajuma wrote:
> lgtm too

lgtm

[commit-bot: I haz the power, 2016-04-13 01:13:52]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-04-13 01:15:02]

Description was changed from

==========
cc: Scroll on main when possible incorrect hit testing hits scrollbar.

As explained in crrev.com/238803005, it is possible that the composited
layers have holes, if the point hits the first layer below the viewport
point and the scrollbar layer, and the scrollbar layer is not an ancestor
of the former layer, we should scroll on main, as shown below:

1) Should scroll on main:

+--.....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+--....
+----....composited_unscrollable_layer (<-viewport point hits this)

2) Can scroll on impl:
+--....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+----....composited_unscrollable_layer (<-viewport point hits this)

BUG=601342
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
==========

to

==========
cc: Scroll on main when possible incorrect hit testing hits scrollbar.

As explained in crrev.com/238803005, it is possible that the composited
layers have holes, if the point hits the first layer below the viewport
point and the scrollbar layer, and the scrollbar layer is not an ancestor
of the former layer, we should scroll on main, as shown below:

1) Should scroll on main:

+--.....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+--....
+----....composited_unscrollable_layer (<-viewport point hits this)

2) Can scroll on impl:
+--....
+----scroll_layer
+----scrollbar_layer (<-viewport point hits this)
+----....composited_unscrollable_layer (<-viewport point hits this)

BUG=601342
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Committed: https://crrev.com/0b34eb5f70ea985690e856d6f58284835e629c75
Cr-Commit-Position: refs/heads/master@{#386880}
==========

[commit-bot: I haz the power, 2016-04-13 01:15:03]

Patchset 2 (id:??) landed as
https://crrev.com/0b34eb5f70ea985690e856d6f58284835e629c75
Cr-Commit-Position: refs/heads/master@{#386880}