Remove more unused landmines code

Follow-up to https://codereview.chromium.org/2071463002/

BUG=none

Review-Url: https://codereview.chromium.org/2193023003
Cr-Original-Commit-Position: refs/heads/master@{#408871}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 8205ee9cf8ad521a3c4efcbc505e53f4d53eadc6

get_landmines.py

@@ -43,14 +43,6 @@ def print_landmines():
   if platform() in ('win', 'mac'):
     print ('Improper dependency for create_nmf.py broke in r240802, '
            'fixed in r240860.')
-  if (platform() == 'win' and
-      gyp_msvs_version() == '2012' and
-      gyp_defines().get('target_arch') == 'x64' and
-      gyp_defines().get('dcheck_always_on') == '1'):
-    print "Switched win x64 trybots from VS2010 to VS2012."
-  if (platform() == 'win' and
-      gyp_msvs_version().startswith('2013')):
-    print "Switch to VS2013"
   if (platform() == 'win' and gyp_msvs_version().startswith('2015')):
     print 'Switch to VS2015 Update 2'
   print 'Need to clobber everything due to an IDL change in r154579 (blink)'