Optimize font fallback for Chinese fonts on Mac

Optimize font fallback for Chinese fonts on Mac

Change font fallback on Mac OS X and iOS to prefer higher quality fonts.
Prefer system-ui which maps to the default font for each OS version then
fall back on a series of fonts in descending order of rendering quality.

BUG=642889
R=shrike@chromium.org

Review-Url: https://codereview.chromium.org/2679193006
Cr-Commit-Position: refs/heads/master@{#457609}
Committed: https://chromium.googlesource.com/chromium/src/+/9b998d1b33fa699e3580e35bc817580706931d13

[eae, 2017-02-09 23:14:42]

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

[commit-bot: I haz the power, 2017-02-09 23:15:27]

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, 2017-02-10 00:10:02]

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

[commit-bot: I haz the power, 2017-02-10 00:10:03]

Dry run: This issue passed the CQ dry run.

[shrike, 2017-02-10 22:26:43]

I'm not a fonts/fonts fallback expert so I can't vouch for the full correctness,
but the changes make sense to me - lgtm.

I'm pretty sure I don't have ownership of this code so you'll have to add
another reviewer to be able to land it.

[eae, 2017-02-21 22:42:10]

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

[eae, 2017-02-21 22:42:10]

+jshin

[jungshik at Google, 2017-03-01 22:49:34]

On 2017/02/21 22:42:10, eae wrote:
> +jshin

Sorry for the late reply.  As long as "system-ui" is resolved to an
locale-appropriate UI font (or a series of UI fonts) by Blink , this looks good.


BTW, that being the case, do we need any other fonts listed including the last
generic (sans-serif)?

[eae, 2017-03-01 22:54:45]

Description was changed from

==========
Optimize font fallback for Chinese fonts on Mac

Change font fallback on Mac OS X and iOS to prefer higher quality fonts.
Prefer system-ui which maps to the default font for each OS version then
fall back on a series of fonts in descending order of rendering quality.

BUG=642889
R=shrike@chromium.org
==========

to

==========
Optimize font fallback for Chinese fonts on Mac

Change font fallback on Mac OS X and iOS to prefer higher quality fonts.
Prefer system-ui which maps to the default font for each OS version then
fall back on a series of fonts in descending order of rendering quality.

BUG=642889
R=shrike@chromium.org
==========

[eae, 2017-03-01 22:54:45]

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

[eae, 2017-03-01 22:55:01]

On 2017/03/01 22:49:34, jungshik at Google wrote:
> On 2017/02/21 22:42:10, eae wrote:
> > +jshin
> 
> Sorry for the late reply.  As long as "system-ui" is resolved to an
> locale-appropriate UI font (or a series of UI fonts) by Blink , this looks
good.
> 
> 
> BTW, that being the case, do we need any other fonts listed including the last
> generic (sans-serif)?

I don't think so. Koji, do you know?

[kojii, 2017-03-02 05:56:14]

> > BTW, that being the case, do we need any other fonts listed including the
last
> > generic (sans-serif)?
> 
> I don't think so. Koji, do you know?

Agree, we probably can remove it, it doesn't do any effect as far as I'm aware
of.

> > As long as "system-ui" is resolved to an
> > locale-appropriate UI font (or a series of UI fonts) by Blink , this looks
good.

"system-ui" is resolved by OS, not by Blink, depends on system locale, font
size, weight, style, etc., to e.g.:
".SFNSText-Regular" => [
    0 => ".AppleSystemFallback-Regular"
    1 => ".LucidaGrandeUI"
    2 => ".AppleSymbolsFB"
    3 => ".GeezaProInterface"
    4 => "Thonburi"
    5 => "Kokonor"
    6 => {
      "zh-Hans" => ".AppleSimplifiedChineseFont-Regular"
      "ko" => ".AppleKoreanFont-Regular"
      "zh-Hant" => ".AppleTraditionalChineseFont-Regular"
      "zh-HK" => ".AppleHongKongChineseFont-Regular"
      "ja" => ".AppleJapaneseFont-Regular"
    }
    7 => "KohinoorBangla-Regular"
    8 => "KohinoorDevanagari-Regular"
    9 => "GujaratiSangamMN"
    10 => "GurmukhiMN"
    11 => "KannadaSangamMN"
    12 => "KhmerSangamMN"
    13 => "LaoSangamMN"
    14 => "MalayalamSangamMN"
    15 => "MyanmarSangamMN"
    16 => "OriyaSangamMN"
    17 => "SinhalaSangamMN"
    18 => "TamilSangamMN"
    19 => "KohinoorTelugu-Regular"
    20 => "Mshtakan"
    21 => "EuphemiaUCAS"
    22 => "PlantagenetCherokee"
    23 => ".NotoSansUniversal"
    24 => "AppleColorEmoji"
  ]
The list may change by OS versions so we shouldn't depend on this, but it should
cover quite well.

Note, only on Mac, we have an open issue http://crbug.com/627609; it applies to
"system-ui" too. Maybe we want to wait for M59?

[eae, 2017-03-08 06:51:18]

Now that 58 has forked should we give this a go?

[jungshik at Google, 2017-03-08 06:54:31]

On 2017/03/08 06:51:18, eae wrote:
> Now that 58 has forked should we give this a go?

If 'system-ui' works the same way (as described above) on all Mac OS versions we
want to support, do we need anything other than 'system-ui'? Or, did I
misunderstand what kojii wrote?

[kojii, 2017-03-08 07:40:04]

I'm fine either way. We can remove it as far as I can think of, but I also don't
see any harm if we keep.

It should discover issues in "system-ui" if any are still there, having it at
top is great.

[jungshik at Google, 2017-03-16 18:11:51]

> I'm fine either way. We can remove it as far as I can think of, but I also
don't
> see any harm if we keep.

The only downside is a ti....ny increase in the download size, but it should not
be a factor. 
 
> It should discover issues in "system-ui" if any are still there, having it at
> top is great.

Either way is fine with me, too. Would you venture to list only 'system-ui' to
discover any issue with 'system-ui' support in Blink in dev builds? 

Anyway, either way is fine. LGTM

[eae, 2017-03-16 18:13:48]

On 2017/03/16 18:11:51, jungshik at Google wrote:
> > I'm fine either way. We can remove it as far as I can think of, but I also
> don't
> > see any harm if we keep.
> 
> The only downside is a ti....ny increase in the download size, but it should
not
> be a factor. 
>  
> > It should discover issues in "system-ui" if any are still there, having it
at
> > top is great.
> 
> Either way is fine with me, too. Would you venture to list only 'system-ui' to
> discover any issue with 'system-ui' support in Blink in dev builds? 
> 
> Anyway, either way is fine. LGTM

Let's try this first and then experiment with removing all but system-ui on dev.
Thanks!

[eae, 2017-03-16 18:13:53]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2017-03-16 18:14:41]

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, 2017-03-16 19:47:38]

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

[commit-bot: I haz the power, 2017-03-16 19:47:39]

Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[eae, 2017-03-16 22:03:40]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2017-03-16 22:04:07]

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, 2017-03-16 23:48:37]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1489701820873780, "parent_rev":
"db917052bfb936546b2602cdb657c310778c6451", "commit_rev":
"9b998d1b33fa699e3580e35bc817580706931d13"}

[commit-bot: I haz the power, 2017-03-16 23:49:26]

Description was changed from

==========
Optimize font fallback for Chinese fonts on Mac

Change font fallback on Mac OS X and iOS to prefer higher quality fonts.
Prefer system-ui which maps to the default font for each OS version then
fall back on a series of fonts in descending order of rendering quality.

BUG=642889
R=shrike@chromium.org
==========

to

==========
Optimize font fallback for Chinese fonts on Mac

Change font fallback on Mac OS X and iOS to prefer higher quality fonts.
Prefer system-ui which maps to the default font for each OS version then
fall back on a series of fonts in descending order of rendering quality.

BUG=642889
R=shrike@chromium.org

Review-Url: https://codereview.chromium.org/2679193006
Cr-Commit-Position: refs/heads/master@{#457609}
Committed:
https://chromium.googlesource.com/chromium/src/+/9b998d1b33fa699e3580e35bc817...
==========

[commit-bot: I haz the power, 2017-03-16 23:49:27]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/9b998d1b33fa699e3580e35bc817...