Rename GrAtlasedLayer to GrCachedLayer (since not all cached layers are atlased)

Rename GrAtlasedLayer to GrCachedLayer (since not all cached layers are atlased)

This is mainly a renaming CL but it does add a ref-counted ptr  to the backing GrTexture for non-atlased layers (the only kind working right now)

Committed: http://code.google.com/p/skia/source/detail?r=14152

[jvanverth1, 2014-04-10 20:40:08]

LGTM. I'm just a little confused though -- is the texture currently set or is
that a later change?

[robertphillips, 2014-04-11 11:11:04]

That change is in my check-that-pre-rendering-saveLayers-is-worth-it hack
(https://codereview.chromium.org/227603006/). I think I may be able to extract
that portion of the hacked SkGpuDevice.cpp but it is going to require a lot more
cleaning up then this chunk (particularly around texture cache use).

[robertphillips, 2014-04-11 11:11:25]

The CQ bit was checked by robertphillips@google.com

[commit-bot: I haz the power, 2014-04-11 11:11:33]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/robertphillips@google.com/233703003/1

[commit-bot: I haz the power, 2014-04-11 15:53:52]

Change committed as 14152