Add workaround for invalid non-bmp character measurements in SVG

Add workaround for invalid non-bmp character measurements in SVG

Before [1], invalid non-bmp characters were measured incorrectly but
did not crash. This patch adds a workaround to
updateSubrunRangesForCurrentPosition so it behaves more like
ShapeResultBuffer::getCharacterRange in the presence of invalid non-bmp
characters. https://crbug.com/595960 has been filed to investigate the
root cause of this.

[1] https://chromium.googlesource.com/chromium/src/+/a3a50c140c60eb242df3dd4df06fe55cad117c75

BUG=595393
Committed: https://crrev.com/44a62c2cb9fa76ebae1aac0845dd9ed509b08e09
Cr-Commit-Position: refs/heads/master@{#382727}

[pdr., 2016-03-18 05:17:00]

pdr@chromium.org changed reviewers:
+ eae@chromium.org

[pdr., 2016-03-18 05:17:06]

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

[commit-bot: I haz the power, 2016-03-18 05:17:17]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1816453002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1816453002/1

[commit-bot: I haz the power, 2016-03-18 06:44:17]

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

[commit-bot: I haz the power, 2016-03-18 06:44:18]

Dry run: This issue passed the CQ dry run.

[pdr., 2016-03-19 00:08:46]

pdr@chromium.org changed reviewers:
+ drott@chromium.org

[pdr., 2016-03-19 00:08:57]

+reviewer drott

[eae, 2016-03-19 00:24:20]

LGTM for now but we better find the root cause

[pdr., 2016-03-19 00:33:46]

On 2016/03/19 at 00:24:20, eae wrote:
> LGTM for now but we better find the root cause

Thanks Emil. I'd like to give drott a chance to see this before committing since
he commented on https://crbug.com/595960.

@drott, if this looks good to you, please CQ.

[pdr., 2016-03-22 16:13:25]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2016-03-22 16:13:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1816453002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1816453002/1

[drott, 2016-03-22 16:56:21]

On 2016/03/19 at 00:33:46, pdr wrote:
> On 2016/03/19 at 00:24:20, eae wrote:
> > LGTM for now but we better find the root cause
> 
> Thanks Emil. I'd like to give drott a chance to see this before committing
since he commented on https://crbug.com/595960.
> 
> @drott, if this looks good to you, please CQ.

Sorry, I missed this comment somehow. I think it's fine to put a check like
this. I fixed one major issue in the normalizeCharacters function caused by
integer truncation. Now that this is done, we should perhaps move this check
from here to further down the line, in the form of an assertion about string
length equality pre and post normalization in HarfBuzzShaper.

[commit-bot: I haz the power, 2016-03-22 19:57:27]

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

[commit-bot: I haz the power, 2016-03-22 19:57:29]

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

[pdr., 2016-03-22 19:58:32]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2016-03-22 19:59:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1816453002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1816453002/1

[commit-bot: I haz the power, 2016-03-22 23:23:32]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-22 23:25:09]

Description was changed from

==========
Add workaround for invalid non-bmp character measurements in SVG

Before [1], invalid non-bmp characters were measured incorrectly but
did not crash. This patch adds a workaround to
updateSubrunRangesForCurrentPosition so it behaves more like
ShapeResultBuffer::getCharacterRange in the presence of invalid non-bmp
characters. https://crbug.com/595960 has been filed to investigate the
root cause of this.

[1]
https://chromium.googlesource.com/chromium/src/+/a3a50c140c60eb242df3dd4df06f...

BUG=595393
==========

to

==========
Add workaround for invalid non-bmp character measurements in SVG

Before [1], invalid non-bmp characters were measured incorrectly but
did not crash. This patch adds a workaround to
updateSubrunRangesForCurrentPosition so it behaves more like
ShapeResultBuffer::getCharacterRange in the presence of invalid non-bmp
characters. https://crbug.com/595960 has been filed to investigate the
root cause of this.

[1]
https://chromium.googlesource.com/chromium/src/+/a3a50c140c60eb242df3dd4df06f...

BUG=595393

Committed: https://crrev.com/44a62c2cb9fa76ebae1aac0845dd9ed509b08e09
Cr-Commit-Position: refs/heads/master@{#382727}
==========

[commit-bot: I haz the power, 2016-03-22 23:25:10]

Patchset 1 (id:??) landed as
https://crrev.com/44a62c2cb9fa76ebae1aac0845dd9ed509b08e09
Cr-Commit-Position: refs/heads/master@{#382727}