remove premature discard optimization

remove premature discard optimization

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/884200ef76bbd25ab31e061a24cc8c8268dacca0

[reed1, 2015-06-29 15:45:36]

reed@google.com changed reviewers:
+ bsalomon@google.com

[reed1, 2015-06-29 15:45:36]

ptal

[reed1, 2015-06-29 15:45:40]

The CQ bit was checked by reed@google.com

[commit-bot: I haz the power, 2015-06-29 15:45:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1212613005/1

[commit-bot: I haz the power, 2015-06-29 15:45:53]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-06-29 21:45 UTC

[bsalomon, 2015-06-29 15:46:58]

On 2015/06/29 15:45:53, commit-bot: I haz the power wrote:
> Note for Reviewers:
> The CQ is waiting for an approval.
> If you believe that the CL is not ready yet, or if you would like to L-G-T-M
> with comments then please uncheck the CQ checkbox.
> 
> Waiting for LGTM from valid reviewer(s) till 2015-06-29 21:45 UTC

lgtm

[commit-bot: I haz the power, 2015-06-29 16:00:25]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/884200ef76bbd25ab31e061a24cc8c8268dacca0