Revert "Defer more renderTargetContexts in the GPU image filter paths"

This reverts commit fd01ce05ef7902c49b0272b3524a389693c72b35.

Reason for revert: see if this is the cause of the Nexus7 assertion failure

Original change's description:
> Defer more renderTargetContexts in the GPU image filter paths
> 
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4767
> 
> Change-Id: I4c1f27247ef340a49d1ac96761810e77e6047ca2
> Reviewed-on: https://skia-review.googlesource.com/4767
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Robert Phillips <robertphillips@google.com>
> 

TBR=bsalomon@google.com,robertphillips@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I158f96ec1252481345fc5dca15086ffd4b47cb95
Reviewed-on: https://skia-review.googlesource.com/4875
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
8 files changed