Revert of Defer glClear to just before draw call

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:

Committed: https://skia.googlesource.com/skia/+/7156b09c4bc25af772826d5ac592dcdacdf15317

[robertphillips, 2015-05-14 15:53:45]

Created Revert of Defer glClear to just before draw call

[commit-bot: I haz the power, 2015-05-14 15:54:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1136393005/1

[commit-bot: I haz the power, 2015-05-14 15:54:20]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/7156b09c4bc25af772826d5ac592dcdacdf15317