Autoscroll new background tabs on iPad

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 bba53c6b5a3d562ebdfbb7f4c3116d13ed08b281..35de365386ea966ffa7dbcd783a935f06f439577 100644
--- a/ios/chrome/browser/about_flags.mm
+++ b/ios/chrome/browser/about_flags.mm
@@ -98,6 +98,13 @@ void AppendSwitchesFromExperimentalSettings(base::CommandLine* command_line) {
                                     BUILDFLAG(GOOGLE_TEST_OAUTH_CLIENT_SECRET));
   }
 
+  // Populate command line flag for the tab strip auto scroll new tabs
+  // experiment from the configuration plist.
+  if ([defaults boolForKey:@"TabStripAutoScrollNewTabsDisabled"])
+    command_line->AppendSwitch(switches::kDisableTabStripAutoScrollNewTabs);
+  else
+    command_line->AppendSwitch(switches::kEnableTabStripAutoScrollNewTabs);
+
   // Populate command line flag for the Tab Switcher experiment from the
   // configuration plist.
   NSString* enableTabSwitcher = [defaults stringForKey:@"EnableTabSwitcher"];