- use C++11 features ({} init, move constructors) to eliminate the need
for explicit constructors
- collapse RECORD0...RECORD8 into just one RECORD macro
- explicitly tag record types instead of using member detectors.
Removing member detectors makes this code significantly less fragile.
This exposes a few places where we didn't really think through what to do
with SkDrawable. I've marked them TODO for now.
BUG=skia:
Review URL: https://codereview.chromium.org/1360943003
449d9b7e2d