Rm makeRenderTargetContext in favor of deferred version (take 3)

Rm makeRenderTargetContext in favor of deferred version (take 3)

This is a reland of: https://skia-review.googlesource.com/c/13001/ (Rm makeRenderTargetContext in favor of deferred version)

TBR=bsalomon@google.com

Change-Id: If81f4d9fb889c091cd37ffde133d906fb3e37773
Reviewed-on: https://skia-review.googlesource.com/14027
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>