Updates subpixel positioning and hinting when DSF is changed

Updates subpixel positioning and hinting when DSF is changed

See the bug to see the screenshot of problematic rendering
and the result of this fix.

There are several TODOs though:
- Renderers still remember the old font params.
- Changing hinting params will change the bounding box of the
  text, which means we should re-layout several views. This will
  be addressed by other CLs.
- Ideally, the font render params should change based on the display
  where the text is rendered.

BUG=441439
R=oshima@chromium.org, derat@chromium.org, msw@chromium.org
TEST=the new test case covers

Committed: https://crrev.com/5dad2e71ac9f6b229590e23d2ddfef99dceb11b9
Cr-Commit-Position: refs/heads/master@{#308462}

[Daniel Erat, 2014-12-09 16:24:35]

a high-level comment. also, could you open a separate bug to track this (and
describe in more detail what you're trying to do)? i filed
http://crbug.com/396659 to track removing the subpixel positioning flags, and
this doesn't feel directly related to that.

https://codereview.chromium.org/789583002/diff/60001/ui/gfx/font_render_params.h
File ui/gfx/font_render_params.h (right):

https://codereview.chromium.org/789583002/diff/60001/ui/gfx/font_render_param...
ui/gfx/font_render_params.h:89: class GFX_EXPORT FontRenderParamsRewriter {
i don't think i like this being a general interface, or the additional
complexity it adds to FontRenderParams -- it feels very chrome-os-specific. if
we need to do customization, why can't it be done within GetFontRenderParams()
(e.g. after adding necessary additional fields to FontRenderParamsQuery)?

[Jun Mukai, 2014-12-11 23:58:47]

Uploaded a new patchset, I believe this addresses the comments.
PTAL.

[Jun Mukai, 2014-12-12 00:04:49]

replying the comment...

https://codereview.chromium.org/789583002/diff/60001/ui/gfx/font_render_params.h
File ui/gfx/font_render_params.h (right):

https://codereview.chromium.org/789583002/diff/60001/ui/gfx/font_render_param...
ui/gfx/font_render_params.h:89: class GFX_EXPORT FontRenderParamsRewriter {
On 2014/12/09 16:24:35, Daniel Erat wrote:
> i don't think i like this being a general interface, or the additional
> complexity it adds to FontRenderParams -- it feels very chrome-os-specific. if
> we need to do customization, why can't it be done within GetFontRenderParams()
> (e.g. after adding necessary additional fields to FontRenderParamsQuery)?

Removed this class.

[Daniel Erat, 2014-12-12 15:54:58]

thanks! i'm happier with this approach, but one more suggestion. :-)

https://codereview.chromium.org/789583002/diff/100001/ui/gfx/platform_font_pa...
File ui/gfx/platform_font_pango.h (right):

https://codereview.chromium.org/789583002/diff/100001/ui/gfx/platform_font_pa...
ui/gfx/platform_font_pango.h:99: mutable float device_scale_factor_;
instead of making these mutable, would you mind just making
GetFontRenderParams() be non-const?

[Jun Mukai, 2014-12-12 19:40:12]

https://codereview.chromium.org/789583002/diff/100001/ui/gfx/platform_font_pa...
File ui/gfx/platform_font_pango.h (right):

https://codereview.chromium.org/789583002/diff/100001/ui/gfx/platform_font_pa...
ui/gfx/platform_font_pango.h:99: mutable float device_scale_factor_;
On 2014/12/12 15:54:58, Daniel Erat wrote:
> instead of making these mutable, would you mind just making
> GetFontRenderParams() be non-const?

Done.

[Daniel Erat, 2014-12-12 19:59:06]

lgtm

[Jun Mukai, 2014-12-12 20:25:08]

mukai@chromium.org changed reviewers:
+ msw@chromium.org

[Jun Mukai, 2014-12-12 20:26:19]

msw, could you review this?  asvitkine is off until January...

[msw, 2014-12-15 21:13:23]

441495 must be the wrong bug number. I'm missing some context without the
correct bug number, but I think I understand what's going on. lgtm

[Jun Mukai, 2014-12-15 21:16:38]

On 2014/12/15 21:13:23, msw wrote:
> 441495 must be the wrong bug number. I'm missing some context without the
> correct bug number, but I think I understand what's going on. lgtm

oops, I meant 441439 (updated the bug description). And thanks for the review.

[Jun Mukai, 2014-12-15 22:28:39]

The CQ bit was checked by mukai@chromium.org

[commit-bot: I haz the power, 2014-12-15 22:30:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/789583002/140001

[commit-bot: I haz the power, 2014-12-15 22:39:44]

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

[commit-bot: I haz the power, 2014-12-15 22:39:45]

Try jobs failed on following builders:
  linux_chromium_gn_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Jun Mukai, 2014-12-15 22:48:13]

The CQ bit was checked by mukai@chromium.org

[commit-bot: I haz the power, 2014-12-15 22:48:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/789583002/160001

[commit-bot: I haz the power, 2014-12-16 00:00:47]

Committed patchset #9 (id:160001)

[commit-bot: I haz the power, 2014-12-16 00:01:43]

Patchset 9 (id:??) landed as
https://crrev.com/5dad2e71ac9f6b229590e23d2ddfef99dceb11b9
Cr-Commit-Position: refs/heads/master@{#308462}