Layer changes

Bug: 17208461

* Switch Layer to be VirtualLightRefBase instead of
  Caches' side-channel ref-counting
* Include active layers in gfxinfo dump
* Run gfxinfo dump on the correct thread
* Dump gfxinfo on Layer creation failure

Change-Id: I28d195699e2334518e215ab28c7a17355aee9678
26 files changed