Added missing flag to render process

Added missing flag to render process

Follow up to https://codereview.chromium.org/605373002/
The flag was working fine to disable the YUV decoding (which was the goal for M39), but didn't seem to work to enable it. Adding it to render_process_host_impl.cc seems to fix this issue.

BUG=

Committed: https://crrev.com/8150c2c4c2b4ac8df6f17f932d6d102aa87a909c
Cr-Commit-Position: refs/heads/master@{#299887}

[sugoi1, 2014-10-15 20:46:59]

sugoi@chromium.org changed reviewers:
+ piman@google.com

[piman, 2014-10-16 02:15:05]

piman@chromium.org changed reviewers:
+ piman@chromium.org

[piman, 2014-10-16 02:15:06]

LGTM

[sugoi1, 2014-10-16 12:12:08]

The CQ bit was checked by sugoi@chromium.org

[commit-bot: I haz the power, 2014-10-16 12:12:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/661583003/1

[commit-bot: I haz the power, 2014-10-16 14:19:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-16 14:20:34]

Patchset 1 (id:??) landed as
https://crrev.com/8150c2c4c2b4ac8df6f17f932d6d102aa87a909c
Cr-Commit-Position: refs/heads/master@{#299887}