Remove NTP Favicon flag.

ios/chrome/browser/about_flags.mm

Index: ios/chrome/browser/about_flags.mm
diff --git a/ios/chrome/browser/about_flags.mm b/ios/chrome/browser/about_flags.mm
index 96dbc647d1973dfc9435e50ff2e76ca010332edc..66aadb42d6f5e25c5cd3262326bb7b2ad6d35de2 100644
--- a/ios/chrome/browser/about_flags.mm
+++ b/ios/chrome/browser/about_flags.mm
@@ -109,15 +109,6 @@ void AppendSwitchesFromExperimentalSettings(base::CommandLine* command_line) {
     command_line->AppendSwitch(switches::kDisableAllBookmarksView);
   }
 
-  // Populate command line flag for the NTP favicons experiment from the
-  // configuration plist.
-  NSString* enableNTPFavicons = [defaults stringForKey:@"EnableNTPFavicons"];
-  if ([enableNTPFavicons isEqualToString:@"Enabled"]) {
-    command_line->AppendSwitch(switches::kEnableNTPFavicons);
-  } else if ([enableNTPFavicons isEqualToString:@"Disabled"]) {
-    command_line->AppendSwitch(switches::kDisableNTPFavicons);
-  }
-
   // Populate command line flags from PasswordGenerationEnabled.
   NSString* enablePasswordGenerationValue =
       [defaults stringForKey:@"PasswordGenerationEnabled"];