RenderTextMac: Cache the SkTypeface on the TextRun [reland]

RenderTextMac: Cache the SkTypeface on the TextRun [reland]

SkiaTextRenderer::SetFontWithStyle() uses gfx::Font::Derive() which is
slow. SetFontWithStyle is only used on Mac but, also, there was actually
never anything to derive on Mac, since RenderTextMac does (on every
*paint*):
  CTFontRef = <get font from CTRun>
  gfx::Font = <wrap CTFontRef>
  CFFontRef = <unwrap from gfx:Font>  # cheap
  style = <extract style from CTFontRef>
  gfx::Font_2 = Derive(apply <style> to gfx::Font)  # A "no-op", but expensive

So remove SkiaTextRenderer::SetFontWithStyle() since nothing needs it.

Then store the SkTypeface on the RenderTextMac TextRun. This saves a
lookup on each paint and is consistent with RenderTextHarfbuzz.

[reland: prior CL regressed RenderTextTest.Multiline_ZeroWidthChars]

BUG=605131, 605136
Committed: https://crrev.com/59fe54df8c0de55f03c8fb5e1860279d2993b473
Cr-Commit-Position: refs/heads/master@{#389924}

[tapted, 2016-04-26 09:01:07]

Patchset #2 (id:20001) has been deleted

[tapted, 2016-04-26 11:46:20]

tapted@chromium.org changed reviewers:
+ asvitkine@chromium.org

[tapted, 2016-04-26 11:46:20]

Hi Alexei, PTAL. This was reverted because of a subtle problem - the
implementation of CreateSkiaTypeface in render_text_mac.mm was still being
relied on by RenderTextHarfbuzz. I didn't intend to change anything in
RenderTextHarfbuzz, so I've restored the old behaviour. This CreateSkiaTypeface
is the one with the slow .Derive(), but RenderTextHarfbuzz caches the text run
so it should be OK for now.

I added some additional tests, but they're not actually the real reason why that
particular test failed. The cause for that seems to be an orthogonal problem --
http://crbug.com/606705 . tl'dr: rendering a zero-width space "has problems" on
Mac. Avoiding SkTypeface::CreateFromName is the real fix (and
RenderTextTest.Multiline_ZeroWidthChars already has coverage for it).

The other weird part is that it only failed on 10.11. Well, that came up in the
tests I added too. Basically, a default-constructed gfx::Font on Mac starts with
[NSFont systemFontOfSize:..], and these are special on 10.11

Long term.. I probably need to work towards phasing out RenderTextMac, but
that's still contingent on an apples-to-apples performance comparison, and
convincing everyone it's not needed for finer layout control (e.g. text layout
for comboboxes that get a native menu popover).

[Alexei Svitkine (slow), 2016-04-26 14:45:59]

lgtm

[tapted, 2016-04-26 22:31:20]

The CQ bit was checked by tapted@chromium.org

[commit-bot: I haz the power, 2016-04-26 22:31:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1919123002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1919123002/40001

[commit-bot: I haz the power, 2016-04-26 22:38:21]

Committed patchset #2 (id:40001)

[commit-bot: I haz the power, 2016-04-26 22:39:29]

Description was changed from

==========
RenderTextMac: Cache the SkTypeface on the TextRun [reland]

SkiaTextRenderer::SetFontWithStyle() uses gfx::Font::Derive() which is
slow. SetFontWithStyle is only used on Mac but, also, there was actually
never anything to derive on Mac, since RenderTextMac does (on every
*paint*):
  CTFontRef = <get font from CTRun>
  gfx::Font = <wrap CTFontRef>
  CFFontRef = <unwrap from gfx:Font>  # cheap
  style = <extract style from CTFontRef>
  gfx::Font_2 = Derive(apply <style> to gfx::Font)  # A "no-op", but expensive

So remove SkiaTextRenderer::SetFontWithStyle() since nothing needs it.

Then store the SkTypeface on the RenderTextMac TextRun. This saves a
lookup on each paint and is consistent with RenderTextHarfbuzz.

[reland: prior CL regressed RenderTextTest.Multiline_ZeroWidthChars]

BUG=605131, 605136
==========

to

==========
RenderTextMac: Cache the SkTypeface on the TextRun [reland]

SkiaTextRenderer::SetFontWithStyle() uses gfx::Font::Derive() which is
slow. SetFontWithStyle is only used on Mac but, also, there was actually
never anything to derive on Mac, since RenderTextMac does (on every
*paint*):
  CTFontRef = <get font from CTRun>
  gfx::Font = <wrap CTFontRef>
  CFFontRef = <unwrap from gfx:Font>  # cheap
  style = <extract style from CTFontRef>
  gfx::Font_2 = Derive(apply <style> to gfx::Font)  # A "no-op", but expensive

So remove SkiaTextRenderer::SetFontWithStyle() since nothing needs it.

Then store the SkTypeface on the RenderTextMac TextRun. This saves a
lookup on each paint and is consistent with RenderTextHarfbuzz.

[reland: prior CL regressed RenderTextTest.Multiline_ZeroWidthChars]

BUG=605131, 605136

Committed: https://crrev.com/59fe54df8c0de55f03c8fb5e1860279d2993b473
Cr-Commit-Position: refs/heads/master@{#389924}
==========

[commit-bot: I haz the power, 2016-04-26 22:39:30]

Patchset 2 (id:??) landed as
https://crrev.com/59fe54df8c0de55f03c8fb5e1860279d2993b473
Cr-Commit-Position: refs/heads/master@{#389924}