mb: add MB entries for CFI Linux buildbot and enable 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 a08146cf256cdf8d65582bba9c16916adfbe732b..78eb00efdf6ad228f7321fc03f1398dd5cead22c 100644
--- a/tools/mb/mb_config.pyl
+++ b/tools/mb/mb_config.pyl
@@ -39,6 +39,7 @@
     # dont need aura as it is implied by chromeos and ozone.
     'gn_blimp_debug': ['gn', 'chromeos', 'ozone', 'debug'],
 
+    'gn_cfi_bot': ['gn', 'cfi', 'release_bot'],
     'gn_debug_bot': ['gn', 'debug_bot'],
     'gn_debug_bot_minimal_symbols': ['gn', 'debug_bot_minimal_symbols'],
     'gn_debug_bot_minimal_symbols_x86': ['gn', 'debug_bot_minimal_symbols', 'x86'],
@@ -154,6 +155,11 @@
       'gyp_defines': 'chromecast=1',
     },
 
+    'cfi': {
+      'gn_args': 'is_cfi=1',
+      'gyp_defines': 'cfi_vptr=1',
+    },
+
     'chromeos': {
       'gn_args': 'target_os="chromeos"',
       'gyp_defines': 'chromeos=1',
@@ -439,6 +445,7 @@
       'Linux GN (dbg)': 'gn_debug_bot'
     },
     'chromium.fyi': {
+      'CFI Linux': 'gn_cfi_bot',
       'CrWinClang64(dbg)': 'win_clang_debug_bot',
       'Libfuzzer Upload Linux': 'libfuzzer_upload_bot',
       'Site Isolation Linux': 'gn_release_trybot',