CSS Motion Path: Centre transform-origin on the path

CSS Motion Path: Centre transform-origin on the path

This allows HTML elements to remain centred on the path, even as they are rotated.

Links to w3c specifications:
http://dev.w3.org/fxtf/motion-1/
http://dev.w3.org/csswg/css-transforms-2/#ctm

Our implementation is described in
https://lists.w3.org/Archives/Public/public-fx/2015AprJun/0077.html

BUG=416731
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=198560

[Eric Willigers, 2015-07-02 05:57:08]

ericwilligers@chromium.org changed reviewers:
+ dstockwell@chromium.org, shans@chromium.org

[Eric Willigers, 2015-07-03 01:29:40]

Patchset #1 (id:1) has been deleted

[Eric Willigers, 2015-07-03 01:29:48]

Patchset #1 (id:20001) has been deleted

[Eric Willigers, 2015-07-03 02:35:57]

ericwilligers@chromium.org changed reviewers:
+ alancutter@chromium.org, soonm@google.com

[alancutter (OOO until 2018), 2015-07-03 03:08:05]

lgtm with testing nits.

https://codereview.chromium.org/1220793011/diff/40001/LayoutTests/css3/motion...
File LayoutTests/css3/motion-path/combine-rotation.html (right):

https://codereview.chromium.org/1220793011/diff/40001/LayoutTests/css3/motion...
LayoutTests/css3/motion-path/combine-rotation.html:11: transform-origin: 0% 0%;
I think we should leave transform-origin as default and instead update the
expected transform to include translate(-50%, -50%). We're getting less coverage
by zeroing out the origin factor.

https://codereview.chromium.org/1220793011/diff/40001/LayoutTests/css3/motion...
File LayoutTests/css3/motion-path/origin-expected.html (right):

https://codereview.chromium.org/1220793011/diff/40001/LayoutTests/css3/motion...
LayoutTests/css3/motion-path/origin-expected.html:16: transform:
translate(336px, 134px) rotate(135deg);
You can just add a translate(-20%, -40%) here instead of having to calculate the
px value.

[Eric Willigers, 2015-07-03 03:31:38]

https://codereview.chromium.org/1220793011/diff/40001/LayoutTests/css3/motion...
File LayoutTests/css3/motion-path/combine-rotation.html (right):

https://codereview.chromium.org/1220793011/diff/40001/LayoutTests/css3/motion...
LayoutTests/css3/motion-path/combine-rotation.html:11: transform-origin: 0% 0%;
On 2015/07/03 03:08:04, alancutter wrote:
> I think we should leave transform-origin as default and instead update the
> expected transform to include translate(-50%, -50%). We're getting less
coverage
> by zeroing out the origin factor.

Done.

https://codereview.chromium.org/1220793011/diff/40001/LayoutTests/css3/motion...
File LayoutTests/css3/motion-path/origin-expected.html (right):

https://codereview.chromium.org/1220793011/diff/40001/LayoutTests/css3/motion...
LayoutTests/css3/motion-path/origin-expected.html:16: transform:
translate(336px, 134px) rotate(135deg);
On 2015/07/03 03:08:05, alancutter wrote:
> You can just add a translate(-20%, -40%) here instead of having to calculate
the
> px value.

Done.

[shans, 2015-07-05 23:05:12]

lgtm

[soonm, 2015-07-07 23:59:09]

lgtm

[dstockwell, 2015-07-09 00:16:16]

lgtm

[Eric Willigers, 2015-07-09 00:30:40]

The CQ bit was checked by ericwilligers@chromium.org

[Eric Willigers, 2015-07-09 00:30:40]

The patchset sent to the CQ was uploaded after l-g-t-m from
alancutter@chromium.org
Link to the patchset: https://codereview.chromium.org/1220793011/#ps60001
(title: "transform-origin")

[commit-bot: I haz the power, 2015-07-09 00:30:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1220793011/60001

[commit-bot: I haz the power, 2015-07-09 00:34:15]

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

[commit-bot: I haz the power, 2015-07-09 00:34:16]

Try jobs failed on following builders:
  mac_blink_compile_dbg on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/mac_blink_compile_dbg/bu...)
  mac_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/62212)

[Eric Willigers, 2015-07-09 02:46:57]

The CQ bit was checked by ericwilligers@chromium.org

[Eric Willigers, 2015-07-09 02:46:58]

The patchset sent to the CQ was uploaded after l-g-t-m from
dstockwell@chromium.org, shans@chromium.org, alancutter@chromium.org,
soonm@google.com
Link to the patchset: https://codereview.chromium.org/1220793011/#ps80001
(title: "rebase")

[commit-bot: I haz the power, 2015-07-09 02:47:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1220793011/80001

[commit-bot: I haz the power, 2015-07-09 03:55:42]

Committed patchset #3 (id:80001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=198560