Set /SUBSYSTEM down to 5.02 on x64 to more closely match x86

Set /SUBSYSTEM down to 5.02 on x64 to more closely match x86

This makes us get XP/Server 2003 compatible metrics for window
sizes and so indirectly fixes pixels being cut off at the top
of the window.

(Server 2003 compatible metrics make us match x86 behaviour, and
since we need to maintain XP subsystem there indefinitely, I can
sort of rationalize it on that basis.)

R=jschuh@chromium.org, wfh@chromium.org
BUG=361720
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=274853

[jschuh, 2014-06-04 03:07:36]

slightly dirty lgtm

[jschuh, 2014-06-04 03:07:46]

The CQ bit was checked by jschuh@chromium.org

[commit-bot: I haz the power, 2014-06-04 03:09:36]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/scottmg@chromium.org/311953003/1

[commit-bot: I haz the power, 2014-06-04 04:24:15]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)

[Will Harris, 2014-06-04 04:38:06]

lgtm but now you need to test this on Windows XP 64-bit

[scottmg, 2014-06-04 04:42:57]

On 2014/06/04 04:38:06, Will Harris wrote:
> lgtm but now you need to test this on Windows XP 64-bit

I'll definitely get right on that.

[commit-bot: I haz the power, 2014-06-04 05:34:27]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-06-04 05:34:28]

Try jobs failed on following builders:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)

[PhistucK, 2014-06-04 14:07:34]

On 2014/06/04 04:38:06, Will Harris wrote:
> lgtm but now you need to test this on Windows XP 64-bit

The official page says that the 64 bit edition is for Windows 7 and 8, not XP,
so - does it matter?

[jschuh, 2014-06-04 14:18:20]

On 2014/06/04 14:07:34, PhistucK wrote:
> On 2014/06/04 04:38:06, Will Harris wrote:
> > lgtm but now you need to test this on Windows XP 64-bit
> 
> The official page says that the 64 bit edition is for Windows 7 and 8, not XP,
> so - does it matter?

wfh@ was making a joke. :) We will not be supporting anything below Win7 for
x64, but this compatibility setting is the best immediate solution to the
problem.

[scottmg, 2014-06-04 15:48:16]

The CQ bit was checked by scottmg@chromium.org

[commit-bot: I haz the power, 2014-06-04 15:48:49]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/scottmg@chromium.org/311953003/1

[commit-bot: I haz the power, 2014-06-04 17:16:07]

Change committed as 274853