Alter layer hoisting to only hoist layers for one canvas at a time

Alter layer hoisting to only hoist layers for one canvas at a time

This CL alters layer hoisting to defer creation of the free floating layers until they are actually needed (rather than creating _all_ the hoisted layers at the start).

It also fixes a pre vs. post Concat bug with how matrices were being accumulated.

BUG=skia:2315
Committed: https://skia.googlesource.com/skia/+/fd61ed0d7929cf85e0b936f48c72035af4c0a4b3

[robertphillips, 2014-10-23 17:51:43]

robertphillips@google.com changed reviewers:
+ bsalomon@google.com

[robertphillips, 2014-10-23 18:03:07]

robertphillips@google.com changed reviewers:
+ jvanverth@google.com

[robertphillips, 2014-10-23 18:03:07]

robertphillips@google.com changed required reviewers:
+ bsalomon@google.com

[bsalomon, 2014-10-24 15:11:00]

On 2014/10/23 18:03:16, robertphillips wrote:
 (rubber stamp) lgtm

[robertphillips, 2014-10-27 12:13:53]

The CQ bit was checked by robertphillips@google.com

[commit-bot: I haz the power, 2014-10-27 12:14:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/657383004/60001

[commit-bot: I haz the power, 2014-10-27 12:15:30]

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

[commit-bot: I haz the power, 2014-10-27 12:15:31]

Try jobs failed on following builders:
  Test-Ubuntu13.10-GCE-NoGPU-x86_64-Debug-Trybot on client.skia
(http://build.chromium.org/p/client.skia/builders/Test-Ubuntu13.10-GCE-NoGPU-x...)
  Test-Ubuntu13.10-GCE-NoGPU-x86_64-Release-Shared-Trybot on client.skia
(http://build.chromium.org/p/client.skia/builders/Test-Ubuntu13.10-GCE-NoGPU-x...)

[robertphillips, 2014-10-28 14:12:52]

The CQ bit was checked by robertphillips@google.com

[commit-bot: I haz the power, 2014-10-28 14:13:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/657383004/80001

[commit-bot: I haz the power, 2014-10-28 14:21:52]

Committed patchset #5 (id:80001) as fd61ed0d7929cf85e0b936f48c72035af4c0a4b3

[robertphillips, 2014-11-06 14:01:17]

Patchset #6 (id:100001) has been deleted