Compute a more correct "screen scope" transform for SVGSVGElement

Compute a more correct "screen scope" transform for SVGSVGElement

For getScreenCTM, only the position (translation) of the outermost svg
element was computed - any additional transform data was dropped.

Use LayoutObject::localToAbsoluteTransform to compute the full transform
rather than just the position of the layout box. Since using this method
works for any (attached) element, implement getScreenCTM without using
computeCTM, and get rid of the ScreenScope variant of the latter. This
also allows us to simplify SVGSVGElement::localCoordinateSpaceTransform
a bit, and drop the CTMScope argument from the
localCoordinateSpaceTransform declaration(s).

It's not clear from [1] how elements which are not in the rendering tree
(i.e has 'display: none' or similar) should be handled. With this
implementation we will return an identity matrix in those cases, which
doesn't seem unreasonable. (The option would be to return 'null', which
is how elements not in the document should be treated, but we don't have
that semantic implemented yet.)

[1] https://svgwg.org/svg2-draft/types.html#__svg__SVGGraphicsElement__getScreenCTM

BUG=678167
Review-Url: https://codereview.chromium.org/2711503002
Cr-Commit-Position: refs/heads/master@{#451938}
Committed: https://chromium.googlesource.com/chromium/src/+/2ad2a9bf7205ec77843cf27a7964fda92df386b2

[fs, 2017-02-21 13:11:33]

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

[commit-bot: I haz the power, 2017-02-21 13:11:38]

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

[fs, 2017-02-21 13:13:00]

Description was changed from

==========
Compute a more correct "screen scope" transform for SVGSVGElement

For getScreenCTM, only the position (translation) of the outermost svg
element was computed - any additional transform data was dropped.

Use LayoutObject::localToAbsoluteTransform to compute the full transform
rather than just the position of the layout box. Since using this method
works for any (attached) element, implement getScreenCTM without using
computeCTM, and get rid of the ScreenScope variant of the latter. This
also allows us to simplify SVGSVGElement::localCoordinateSpaceTransform
a bit. It's not clear from [1] how elements which are not in the
rendering tree (i.e has 'display: none' or similar) should be handled.

With this implementation we will return an identity matrix in those
cases, which doesn't seem unreasonable. (The option would be to return
'null', which is how elements not in the document should be treated, but
we don't have that semantic implemented yet.)

[1]
https://svgwg.org/svg2-draft/types.html#__svg__SVGGraphicsElement__getScreenCTM

BUG=678167
==========

to

==========
Compute a more correct "screen scope" transform for SVGSVGElement

For getScreenCTM, only the position (translation) of the outermost svg
element was computed - any additional transform data was dropped.

Use LayoutObject::localToAbsoluteTransform to compute the full transform
rather than just the position of the layout box. Since using this method
works for any (attached) element, implement getScreenCTM without using
computeCTM, and get rid of the ScreenScope variant of the latter. This
also allows us to simplify SVGSVGElement::localCoordinateSpaceTransform
a bit, and drop the CTMScope argument from the
localCoordinateSpaceTransform declaration(s).

It's not clear from [1] how elements which are not in the rendering tree
(i.e has 'display: none' or similar) should be handled. With this
implementation we will return an identity matrix in those cases, which
doesn't seem unreasonable. (The option would be to return 'null', which
is how elements not in the document should be treated, but we don't have
that semantic implemented yet.)

[1]
https://svgwg.org/svg2-draft/types.html#__svg__SVGGraphicsElement__getScreenCTM

BUG=678167
==========

[fs, 2017-02-21 14:56:35]

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

[commit-bot: I haz the power, 2017-02-21 14:57:15]

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, 2017-02-21 16:30:54]

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

[commit-bot: I haz the power, 2017-02-21 16:30:55]

Dry run: This issue passed the CQ dry run.

[fs, 2017-02-21 16:54:00]

fs@opera.com changed reviewers:
+ pdr@chromium.org, schenney@chromium.org

[Stephen Chennney, 2017-02-21 18:46:54]

lgtm

[fs, 2017-02-21 21:55:19]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2017-02-21 21:56:53]

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, 2017-02-22 00:00:56]

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

[commit-bot: I haz the power, 2017-02-22 00:00:57]

Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)

[fs, 2017-02-22 08:44:48]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2017-02-22 08:45:25]

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, 2017-02-22 08:50:32]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1487753088754570,
"parent_rev": "c5b606c3188dac60dd3f8e29bafbb90d95089c3e", "commit_rev":
"2ad2a9bf7205ec77843cf27a7964fda92df386b2"}

[commit-bot: I haz the power, 2017-02-22 08:51:09]

Description was changed from

==========
Compute a more correct "screen scope" transform for SVGSVGElement

For getScreenCTM, only the position (translation) of the outermost svg
element was computed - any additional transform data was dropped.

Use LayoutObject::localToAbsoluteTransform to compute the full transform
rather than just the position of the layout box. Since using this method
works for any (attached) element, implement getScreenCTM without using
computeCTM, and get rid of the ScreenScope variant of the latter. This
also allows us to simplify SVGSVGElement::localCoordinateSpaceTransform
a bit, and drop the CTMScope argument from the
localCoordinateSpaceTransform declaration(s).

It's not clear from [1] how elements which are not in the rendering tree
(i.e has 'display: none' or similar) should be handled. With this
implementation we will return an identity matrix in those cases, which
doesn't seem unreasonable. (The option would be to return 'null', which
is how elements not in the document should be treated, but we don't have
that semantic implemented yet.)

[1]
https://svgwg.org/svg2-draft/types.html#__svg__SVGGraphicsElement__getScreenCTM

BUG=678167
==========

to

==========
Compute a more correct "screen scope" transform for SVGSVGElement

For getScreenCTM, only the position (translation) of the outermost svg
element was computed - any additional transform data was dropped.

Use LayoutObject::localToAbsoluteTransform to compute the full transform
rather than just the position of the layout box. Since using this method
works for any (attached) element, implement getScreenCTM without using
computeCTM, and get rid of the ScreenScope variant of the latter. This
also allows us to simplify SVGSVGElement::localCoordinateSpaceTransform
a bit, and drop the CTMScope argument from the
localCoordinateSpaceTransform declaration(s).

It's not clear from [1] how elements which are not in the rendering tree
(i.e has 'display: none' or similar) should be handled. With this
implementation we will return an identity matrix in those cases, which
doesn't seem unreasonable. (The option would be to return 'null', which
is how elements not in the document should be treated, but we don't have
that semantic implemented yet.)

[1]
https://svgwg.org/svg2-draft/types.html#__svg__SVGGraphicsElement__getScreenCTM

BUG=678167

Review-Url: https://codereview.chromium.org/2711503002
Cr-Commit-Position: refs/heads/master@{#451938}
Committed:
https://chromium.googlesource.com/chromium/src/+/2ad2a9bf7205ec77843cf27a7964...
==========

[commit-bot: I haz the power, 2017-02-22 08:51:10]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/2ad2a9bf7205ec77843cf27a7964...