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)

R=jvanverth@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/233703003

git-svn-id: http://skia.googlecode.com/svn/trunk@14152 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed