Revert of Defer glClear to just before draw call (patchset #2 id:20001 of https://codereview.chromium.org/1113003005/)

Reason for revert:
This CL seems to be triggering the assert:
src/gpu/SkGpuDevice.cpp:319: failed assertion "!fNeedClear"
on, at least, Mac & Ubuntu.

Original issue's description:
> Defer glClear to just before draw call
>
> Remove some DO_DEFERRED_CLEAR call to avoid call glClear separately, like this:
> glBindFramebuffer(1)
> glClear
> glBindFramebuffer(2)
> glClear
> glBindFramebuffer(1)
> glDrawXXX
> glBindFramebuffer(2)
> glDrawXXX
>
> These call sequences may need read and write memory back and forth.
>
> If we call DO_DEFERRED_CLEAR just before draw call, we can bind, clear and draw in one go.
> e.g.
> glBindFramebuffer(1)
> glClear
> glDrawXXX
> glBindFramebuffer(2)
> glClear
> glDrawXXX
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/c3c06a13e69b90d4cc1d543853504072d363ae8b

TBR=bsalomon@google.com,joel.liang@arm.com,wasim.abbas@arm.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1136393005
1 file changed