[Prerender] Avoid setting prerender requests for sync XHRs to IDLE priority

[Prerender] Avoid setting prerender requests for sync XHRs to IDLE priority

This triggered a DCHECK in https://codereview.chromium.org/51683002/ .

BUG=166689
R=davidben@chromium.org, jam@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=233305

[akalin, 2013-11-06 00:30:13]

+davidben for review

I decided to instead let the requests go through and not set it to IDLE priority
if it's a sync XHR. What do you think?

[davidben, 2013-11-06 16:00:17]

On 2013/11/06 00:30:13, akalin wrote:
> +davidben for review
> 
> I decided to instead let the requests go through and not set it to IDLE
priority
> if it's a sync XHR. What do you think?

LGTM.

[commit-bot: I haz the power, 2013-11-06 17:42:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/akalin@chromium.org/60193004/1

[commit-bot: I haz the power, 2013-11-06 18:01:14]

Retried try job too often on chromium_presubmit for step(s) presubmit
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=chromium_p...

[akalin, 2013-11-06 18:12:20]

+jam for OWNERS

[jam, 2013-11-06 18:36:18]

lgtm

[akalin, 2013-11-06 18:37:55]

Committed patchset #1 manually as r233305 (presubmit successful).