Rm makeRenderTargetContext in favor of deferred version (take 2)

Rm makeRenderTargetContext in favor of deferred version (take 2)

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

Change-Id: Ife77b012d09c46895884a168fc5045bd92a4b919
Reviewed-on: https://skia-review.googlesource.com/13196
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>