Avoid heap allocation in SkPictureStateTree constructor

Avoid heap allocation in SkPictureStateTree constructor

This makes empty state trees cheaper. ~1% improvement on rasterize_and_record_micro.key_silk_cases on Android.

BUG=1772
Committed: http://code.google.com/p/skia/source/detail?r=12616

[tomhudson, 2013-12-10 22:55:24]

lgtm

Is it just me, or does this also fix a memory leak?

[commit-bot: I haz the power, 2013-12-10 22:55:41]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/skyostil@chromium.org/111573002/1

[mtklein, 2013-12-10 22:59:03]

On 2013/12/10 22:55:24, tomhudson wrote:
> lgtm
> 
> Is it just me, or does this also fix a memory leak?

Looks like all the allocations were handled by fAlloc, so they get cleaned for
free when it's destructed?

[tomhudson, 2013-12-10 23:00:42]

On 2013/12/10 22:59:03, mtklein wrote:
> On 2013/12/10 22:55:24, tomhudson wrote:
> > lgtm
> > 
> > Is it just me, or does this also fix a memory leak?
> 
> Looks like all the allocations were handled by fAlloc, so they get cleaned for
> free when it's destructed?

Ah, right.

[commit-bot: I haz the power, 2013-12-10 23:06:58]

Change committed as 12616