Revert 211007 "Switch all windows bots to use Aura."

> Switch all windows bots to use Aura.
> 
> So we can have the perf bots run with aura for a while. Depending how red
> the waterfall we could leave it on for a long time.
> 
> This has happened before and it will happen again.
> See for example r204698
> 
> BUG=259185
> TEST=none
> TBR=scottmg
> 
> Review URL: https://codereview.chromium.org/18434006

TBR=cpu@chromium.org
Review URL: https://codereview.chromium.org/18439004

git-svn-id: http://src.chromium.org/svn/trunk/src/build@211040 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -65,8 +65,8 @@
           'branding%': 'Chromium',
 
           'conditions': [
-            # ChromeOS implies ash and for a limited time Windows. Call now!.
-            ['chromeos==1 or OS=="win"', {
+            # ChromeOS implies ash.
+            ['chromeos==1', {
               'use_ash%': 1,
               'use_aura%': 1,
             }],