Update createWrappedRenderTargetProxy with BackendRT to work with lazy proxies.

This change also triggered a bunch of side changes thanks to WrappedProxyTest
fixing/improving how we handle wrapped proxies in genernal.

Bug: skia:
Change-Id: I743a458923cff1c2e947627d0e9154a4c808a668
Reviewed-on: https://skia-review.googlesource.com/108102
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
12 files changed