Switch all windows bots to use Aura.

Because we've been shipping Aura to canary for a while. And because force compositor landed 40 hours ago and things seem ok. See https://codereview.chromium.org/23874016/

This also allows to see perf numbers for Aura. 

This has happened before see for example r204698, r211007 and 214056 as an experiment but this time it might stick.

BUG=259185
TEST=none
TBR=scottmg

Review URL: https://codereview.chromium.org/23816007

git-svn-id: http://src.chromium.org/svn/trunk/src/build@221936 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -69,8 +69,8 @@
           'branding%': 'Chromium',
 
           'conditions': [
-            # ChromeOS implies ash.
-            ['chromeos==1', {
+            # ChromeOS implies ash and Windows implies Ash and Aura.
+            ['chromeos==1 or OS=="win"', {
               'use_ash%': 1,
               'use_aura%': 1,
             }],