Flip mac, win trunk builders on official.desktop.continuous to GN.

tools/mb/mb_config.pyl

Index: tools/mb/mb_config.pyl
diff --git a/tools/mb/mb_config.pyl b/tools/mb/mb_config.pyl
index d9cf7da9e2fa056fdd4c47112b3e9d43bb2b5fc4..6f4d2b1da1c1311aa12a3046e8ab719a56e9122e 100644
--- a/tools/mb/mb_config.pyl
+++ b/tools/mb/mb_config.pyl
@@ -635,13 +635,13 @@
     'official.desktop.continuous': {
       'mac beta': 'gyp_official',
       'mac stable': 'gyp_official',
-      'mac trunk': 'gyp_official',
+      'mac trunk': 'gn_official',
       'precise64 beta': 'gn_official',
       'precise64 stable': 'gn_official',
       'precise64 trunk': 'gn_official',
       'win beta': 'gyp_official_six_concurrent_links',
       'win stable': 'gyp_official_six_concurrent_links',
-      'win trunk': 'gyp_official_six_concurrent_links',
+      'win trunk': 'gn_official_six_concurrent_links',
     },
 
     'tryserver.blink': {
@@ -1330,6 +1330,10 @@
       'gyp', 'official', 'syzyasan',
     ],
 
+    'gn_official_six_concurrent_links': [
+      'gn', 'official', 'six_concurrent_links',
+    ],
+
     'gyp_official_six_concurrent_links': [
       'gyp', 'official', 'six_concurrent_links',
     ],