Performance fix for high dpi devices.

Fix for performance regression on high dpi devices.

ComputedStyle::getRoundedInnerBorderFor() could generate negative
content boxes for boxes with no content and sub pixel borders that
round up (eg. 1.5px-1.99px).  Negative content boxes are illegal per
spec, and causes BoxBorderPainter::paintBorderFastPath() to bail,
and performance to be substantially degraded.

This issue would be evident on the paint-offset-changes perftest when
device pixel ratio was set to eg. 1.5.  The issue was introduced in
934becac5daa91ea979fb66e4ae21761ca11ebc9

BUG=692955
Review-Url: https://codereview.chromium.org/2771093003
Cr-Commit-Position: refs/heads/master@{#459770}
Committed: https://chromium.googlesource.com/chromium/src/+/dd547f46cfb46ea92f554aa842d06bde19ceef6e

[Karl Øygard, 2017-03-24 11:09:33]

The CQ bit was checked by karlo@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2017-03-24 11:09:50]

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

[Karl Øygard, 2017-03-24 12:12:57]

Description was changed from

==========
Performance fix for high dpi devices.

ComputedStyle::getRoundedInnerBorderFor() could generate negative size
rectangles if the box has no content, and has borders that round up (eg.
1.5px-1.99px).  This would cause BoxBorderPainter::paintBorderFastPath()
to fail, and performance to be substantially degraded.

BUG=692955
==========

to

==========
Fix for performance regression on high dpi devices.

ComputedStyle::getRoundedInnerBorderFor() could generate negative size
rectangles if the box has no content, and has borders that round up (eg.
1.5px-1.99px).  This would cause BoxBorderPainter::paintBorderFastPath()
to fail, and performance to be substantially degraded.

This issue would be evident on the paint-offset-changes perftest when
device pixel ratio was set to eg. 1.5.  The issue was introduced in
934becac5daa91ea979fb66e4ae21761ca11ebc9

BUG=692955
==========

[commit-bot: I haz the power, 2017-03-24 12:51:30]

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

[commit-bot: I haz the power, 2017-03-24 12:51:31]

Dry run: This issue passed the CQ dry run.

[rune, 2017-03-24 13:22:59]

rune@opera.com changed reviewers:
+ rune@opera.com

[rune, 2017-03-24 13:22:59]

lgtm, make a note in the description that the content box size cannot be
negative before landing.

[Karl Øygard, 2017-03-27 11:37:03]

Description was changed from

==========
Fix for performance regression on high dpi devices.

ComputedStyle::getRoundedInnerBorderFor() could generate negative size
rectangles if the box has no content, and has borders that round up (eg.
1.5px-1.99px).  This would cause BoxBorderPainter::paintBorderFastPath()
to fail, and performance to be substantially degraded.

This issue would be evident on the paint-offset-changes perftest when
device pixel ratio was set to eg. 1.5.  The issue was introduced in
934becac5daa91ea979fb66e4ae21761ca11ebc9

BUG=692955
==========

to

==========
Fix for performance regression on high dpi devices.

ComputedStyle::getRoundedInnerBorderFor() could generate negative
content boxes for boxes with no content and sub pixel borders that
round up (eg. 1.5px-1.99px).  Negative content boxes are illegal per
spec, and causes BoxBorderPainter::paintBorderFastPath() to bail,
and performance to be substantially degraded.

This issue would be evident on the paint-offset-changes perftest when
device pixel ratio was set to eg. 1.5.  The issue was introduced in
934becac5daa91ea979fb66e4ae21761ca11ebc9

BUG=692955
==========

[Karl Øygard, 2017-03-27 11:38:35]

The CQ bit was checked by karlo@opera.com

[commit-bot: I haz the power, 2017-03-27 11:38:46]

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, 2017-03-27 13:29:13]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1490614715702480, "parent_rev":
"d9bc0ee968d13a9798a8e9b97eb1b1f9514c3808", "commit_rev":
"dd547f46cfb46ea92f554aa842d06bde19ceef6e"}

[commit-bot: I haz the power, 2017-03-27 13:29:57]

Description was changed from

==========
Fix for performance regression on high dpi devices.

ComputedStyle::getRoundedInnerBorderFor() could generate negative
content boxes for boxes with no content and sub pixel borders that
round up (eg. 1.5px-1.99px).  Negative content boxes are illegal per
spec, and causes BoxBorderPainter::paintBorderFastPath() to bail,
and performance to be substantially degraded.

This issue would be evident on the paint-offset-changes perftest when
device pixel ratio was set to eg. 1.5.  The issue was introduced in
934becac5daa91ea979fb66e4ae21761ca11ebc9

BUG=692955
==========

to

==========
Fix for performance regression on high dpi devices.

ComputedStyle::getRoundedInnerBorderFor() could generate negative
content boxes for boxes with no content and sub pixel borders that
round up (eg. 1.5px-1.99px).  Negative content boxes are illegal per
spec, and causes BoxBorderPainter::paintBorderFastPath() to bail,
and performance to be substantially degraded.

This issue would be evident on the paint-offset-changes perftest when
device pixel ratio was set to eg. 1.5.  The issue was introduced in
934becac5daa91ea979fb66e4ae21761ca11ebc9

BUG=692955

Review-Url: https://codereview.chromium.org/2771093003
Cr-Commit-Position: refs/heads/master@{#459770}
Committed:
https://chromium.googlesource.com/chromium/src/+/dd547f46cfb46ea92f554aa842d0...
==========

[commit-bot: I haz the power, 2017-03-27 13:29:58]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/dd547f46cfb46ea92f554aa842d0...