Avoid unnecessary work in |RenderTextWin::UpdateLayout()| if there are no runs.

Avoid unnecessary work in |RenderTextWin::UpdateLayout()| if there are no runs.

Avoids calling unnecessary Uniscribe functions until there's text to process.

BUG=none
TEST=none

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=109723

[Alexei Svitkine (slow), 2011-11-10 21:40:27]

msw: review
sky: OWNERS approval

[sky, 2011-11-10 21:49:04]

LGTM

http://codereview.chromium.org/8515012/diff/1/ui/gfx/render_text_win.cc
File ui/gfx/render_text_win.cc (right):

http://codereview.chromium.org/8515012/diff/1/ui/gfx/render_text_win.cc#newco...
ui/gfx/render_text_win.cc:320: HDC hdc = CreateCompatibleDC(NULL);
nit: use ScopedCreateDC.

[Alexei Svitkine (slow), 2011-11-10 22:10:35]

http://codereview.chromium.org/8515012/diff/1/ui/gfx/render_text_win.cc
File ui/gfx/render_text_win.cc (right):

http://codereview.chromium.org/8515012/diff/1/ui/gfx/render_text_win.cc#newco...
ui/gfx/render_text_win.cc:320: HDC hdc = CreateCompatibleDC(NULL);
On 2011/11/10 21:49:04, sky wrote:
> nit: use ScopedCreateDC.

Done.

[msw, 2011-11-10 22:22:08]

http://codereview.chromium.org/8515012/diff/7001/ui/gfx/render_text_win.cc
File ui/gfx/render_text_win.cc (right):

http://codereview.chromium.org/8515012/diff/7001/ui/gfx/render_text_win.cc#ne...
ui/gfx/render_text_win.cc:321: base::win::ScopedCreateDC
hdc(CreateCompatibleDC(NULL));
You can optionally move this (and the runs_.empty check) into LayoutVisualText.
The arg is there in case re-using a DC or sharing one across
shaping/placement/drawing would help perf. But if this pattern is good, then the
arg is not needed.

[Alexei Svitkine (slow), 2011-11-11 14:53:48]

http://codereview.chromium.org/8515012/diff/7001/ui/gfx/render_text_win.cc
File ui/gfx/render_text_win.cc (right):

http://codereview.chromium.org/8515012/diff/7001/ui/gfx/render_text_win.cc#ne...
ui/gfx/render_text_win.cc:321: base::win::ScopedCreateDC
hdc(CreateCompatibleDC(NULL));
On 2011/11/10 22:22:08, msw wrote:
> You can optionally move this (and the runs_.empty check) into
LayoutVisualText.
> The arg is there in case re-using a DC or sharing one across
> shaping/placement/drawing would help perf. But if this pattern is good, then
the
> arg is not needed.

Done.

[Alexei Svitkine (slow), 2011-11-11 18:30:19]

Ping. (Re-sending because Gmail marked my last msg as spam for me - in case it
did for you too.)

[msw, 2011-11-11 19:55:25]

LGTM; thanks!

[commit-bot: I haz the power, 2011-11-11 19:56:51]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/8515012/9002

[commit-bot: I haz the power, 2011-11-11 20:53:31]

Try job failure for 8515012-9002 (retry) on mac_rel for step "compile" (clobber
build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_rel&nu...

[commit-bot: I haz the power, 2011-11-11 20:55:34]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/8515012/9002

[commit-bot: I haz the power, 2011-11-11 23:22:42]

Change committed as 109723