Simplify StyleEngine clean up.

Simplify StyleEngine clean up.

The StyleEngine only lives as long as the document is attached,
and the document is always detached before it is destroyed. This also
means the document for the style engine always has a frame, so we
don't need to conditionally create the CSSFontSelector.

R=eseidel@google.com

Committed: https://chromium.googlesource.com/external/mojo/+/69afc61cfd5515ffc991c5cef0ba3a5b93f345be

[esprehn, 2014-12-18 02:44:41]

esprehn@chromium.org changed reviewers:
+ eseidel@chromium.org

[eseidel1, 2014-12-18 03:36:48]

eseidel@google.com changed reviewers:
+ eseidel@google.com

[eseidel1, 2014-12-18 03:36:49]

lgtm

I think originally i envisioned StyleEngine being stateless  But I suspect it
contains document-lifetime state still so yeah it can just hang off the document
like our other "engines" :)

[esprehn, 2014-12-18 05:37:17]

On 2014/12/18 at 03:36:49, eseidel wrote:
> lgtm
> 
> I think originally i envisioned StyleEngine being stateless  But I suspect it
contains document-lifetime state still so yeah it can just hang off the document
like our other "engines" :)

Maybe you're thinking of StyleResolver? We can probably make that stateless,
StyleEngine will be harder but I can try.

[esprehn, 2014-12-18 05:39:49]

Committed patchset #1 (id:1) manually as
69afc61cfd5515ffc991c5cef0ba3a5b93f345be (presubmit successful).