Do not set background priority in-process on Windows

Do not set background priority in-process on Windows, when tabs are backgrounded.

BUG=381820, 398103
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=286195

[Will Harris, 2014-07-28 21:31:51]

This CL reverts 420603014, as it was breaking Android tests, and replaces it
with a Windows specific change that removes setting background priority from
in-process.

I'll be manually testing this today to make sure it doesn't regress 381820.

[Will Harris, 2014-07-29 01:34:02]

On 2014/07/28 21:31:51, Will Harris wrote:
> This CL reverts 420603014, as it was breaking Android tests, and replaces it
> with a Windows specific change that removes setting background priority from
> in-process.
> 
> I'll be manually testing this today to make sure it doesn't regress 381820.

I am working on a parallel fix (running the process background IPC on the IO
thread)
so if I get that working and tested I'll instead just revert 420603014 and push
that.

[jochen (gone - plz use gerrit), 2014-07-29 08:55:48]

lgtm

[mlamouri (slow - plz ping), 2014-07-29 11:09:27]

On 2014/07/29 08:55:48, jochen wrote:
> lgtm

This CL fixes a breakage in Chrome Android. I'm going to submit this in order to
roll it downstream.

[mlamouri (slow - plz ping), 2014-07-29 11:11:07]

The CQ bit was checked by mlamouri@chromium.org

[commit-bot: I haz the power, 2014-07-29 11:11:59]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/wfh@chromium.org/421373002/20001

[commit-bot: I haz the power, 2014-07-29 14:46:16]

Change committed as 286195