Remove XP and Vista bots from chromium.win and chromium.webkit waterfalls.

masters/master.tryserver.chromium.win/master.cfg

Index: masters/master.tryserver.chromium.win/master.cfg
diff --git a/masters/master.tryserver.chromium.win/master.cfg b/masters/master.tryserver.chromium.win/master.cfg
index 76e7fda26710f875423dff001d410f1d0050693e..ccfe88852a66a7944d34b01cab8afb55ce0c15b4 100644
--- a/masters/master.tryserver.chromium.win/master.cfg
+++ b/masters/master.tryserver.chromium.win/master.cfg
@@ -80,13 +80,6 @@ chromium_builders.append({
   'slavebuilddir': 'win',
 })
 
-chromium_builders.append({
-  'name': 'win_chromium_xp_rel_ng',
-  'factory': m_annotator.BaseFactory('chromium_trybot', timeout=3600),
-  # Share build directory with compatible existing builders to save space.
-  'slavebuilddir': 'win'
-})
-
 # GCE Experimental builders
 chromium_builders.append({
   'name': 'win_chromium_rel_ng_exp',
@@ -107,14 +100,6 @@ chromium_builders.append({
   'slavebuilddir': 'win'
 })
 
-
-chromium_builders.append({
-  'name': 'win_chromium_vista_rel_ng',
-  'factory': m_annotator.BaseFactory('chromium_trybot', timeout=3600),
-  # Share build directory with compatible existing builders to save space.
-  'slavebuilddir': 'win'
-})
-
 chromium_builders.append({
   'name': 'win_archive',
   'factory': m_annotator.BaseFactory('chromium_trybot', timeout=3600),