Add a flag for the password manager force-saving experiment.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 9aae17964417887b0232d3a9fd2c7facb6206c75..0d846277e417f3ea3cb881dee9a0d9c79c85543d 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1145,6 +1145,14 @@ const Experiment kExperiments[] = {
     SINGLE_VALUE_TYPE(switches::kDisablePasswordManagerReauthentication)
   },
   {
+    "enable-password-force-saving",
+    IDS_FLAGS_ENABLE_PASSWORD_FORCE_SAVING_NAME,
+    IDS_FLAGS_ENABLE_PASSWORD_FORCE_SAVING_DESCRIPTION,
+    kOsAll,
+    SINGLE_VALUE_TYPE(
+        password_manager::switches::kEnablePasswordForceSaving)
+  },
+  {
     "enable-password-link",
     IDS_FLAGS_PASSWORD_MANAGER_LINK_NAME,
     IDS_FLAGS_PASSWORD_MANAGER_LINK_DESCRIPTION,