Thread through a flag to force SkPicture::playback() when recording subpictures.

Thread through a flag to force SkPicture::playback() when recording subpictures.

This makes nanobench picture recording benchmarks somewhat useful again,
as opposed to all taking about 5us to run no matter the content.

ATTN Sheriff: this will probably trigger perf.skia.org alerts.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/d711d115d28b9838303dcc232516aa2f552f3a2a

[mtklein_C, 2015-06-30 17:27:11]

mtklein@chromium.org changed reviewers:
+ reed@google.com

[mtklein_C, 2015-06-30 17:27:16]

The CQ bit was checked by mtklein@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-06-30 17:27:35]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219873002/20001

[commit-bot: I haz the power, 2015-06-30 17:43:14]

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

[commit-bot: I haz the power, 2015-06-30 17:43:15]

Dry run: This issue passed the CQ dry run.

[reed1, 2015-07-01 13:57:28]

Is this just for testing internally, or a real feature for clients? i.e. can we
make this flag private some how? Just curious.

lgtm

[mtklein, 2015-07-01 14:03:01]

On 2015/07/01 13:57:28, reed1 wrote:
> Is this just for testing internally, or a real feature for clients? i.e. can
we
> make this flag private some how? Just curious.
> 
> lgtm

I think it's going to be most useful when we want to flatten pictures that come
from SP.  That's definitely useful internally.  I'm unclear if that's useful for
clients.  I don't mind making it more private.

[mtklein, 2015-07-01 14:03:58]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2015-07-01 14:04:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219873002/20001

[commit-bot: I haz the power, 2015-07-01 14:04:40]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/d711d115d28b9838303dcc232516aa2f552f3a2a