Begin removing the style recalc timer

Begin removing the style recalc timer

This CL starts us down the path of removing the style recalc timer. Instead of
actually removing the timer, this CL adjusts when we schedule the timer to
match when we'll schedule the animation frame after we remove the recalc timer.

BUG=337617
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=165689

[esprehn, 2014-01-23 22:13:00]

https://codereview.chromium.org/140763007/diff/1/Source/core/dom/Document.cpp
File Source/core/dom/Document.cpp (right):

https://codereview.chromium.org/140763007/diff/1/Source/core/dom/Document.cpp...
Source/core/dom/Document.cpp:1542: if (m_styleRecalcTimer.isActive() ||
!shouldScheduleLayout())
Are we sure this is safe? It means we'll fail to schedule a style recalc while
sheets are loading. When the sheets are done loading what will schedule the
recalc?

(I don't think you can do this, if the stylesheet was empty we'd never schedule
a recalc at all)

[abarth-chromium, 2014-01-23 22:22:53]

https://codereview.chromium.org/140763007/diff/1/Source/core/dom/Document.cpp
File Source/core/dom/Document.cpp (right):

https://codereview.chromium.org/140763007/diff/1/Source/core/dom/Document.cpp...
Source/core/dom/Document.cpp:1542: if (m_styleRecalcTimer.isActive() ||
!shouldScheduleLayout())
On 2014/01/23 22:13:00, esprehn wrote:
> Are we sure this is safe?

Nope.

> It means we'll fail to schedule a style recalc while
> sheets are loading. When the sheets are done loading what will schedule the
> recalc?

Won't we kick off the process in DOMContentLoaded?

> (I don't think you can do this, if the stylesheet was empty we'd never
schedule
> a recalc at all)

Maybe the better thing to do is to request an animation frame just after
DOMContentLoaded?

[esprehn, 2014-01-23 22:26:35]

On 2014/01/23 22:22:53, abarth wrote:
> https://codereview.chromium.org/140763007/diff/1/Source/core/dom/Document.cpp
> File Source/core/dom/Document.cpp (right):
> 
>
https://codereview.chromium.org/140763007/diff/1/Source/core/dom/Document.cpp...
> Source/core/dom/Document.cpp:1542: if (m_styleRecalcTimer.isActive() ||
> !shouldScheduleLayout())
> On 2014/01/23 22:13:00, esprehn wrote:
> > Are we sure this is safe?
> 
> Nope.
> 
> > It means we'll fail to schedule a style recalc while
> > sheets are loading. When the sheets are done loading what will schedule the
> > recalc?
> 
> Won't we kick off the process in DOMContentLoaded?

Ah yeah, I think shouldScheduleLayout() may also return false if there's sheets
loading after DOMContentLoaded. That means that even once a page has loaded we
might skip this if you did appendChild(<style>) but something must trigger the
layout to happen eventually in that case... (I dunno what?) but that makes me
think this is safe.

lgtm, lets see what happens.

[commit-bot: I haz the power, 2014-01-24 00:21:17]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/140763007/90001

[commit-bot: I haz the power, 2014-01-24 03:23:33]

Change committed as 165689