[Password Manager] Add experiment controlling sync credential saving behavior

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index b0de2b0b0fdb67c3739c2e01a60852027459114f..b2bc6bd7c4851da4739b7a15a629752f4ab5c8f4 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -6186,6 +6186,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_DEBUG_PACKED_APP_DESCRIPTION" desc="Description of the flag to enable debugging context menu options for packed apps.">
         Enables debugging context menu options such as Inspect Element for packed applications.
       </message>
+      <message name="IDS_FLAGS_ENABLE_DROP_SYNC_CREDENTIAL_NAME" desc="Name of the flag to enable drop sync credential">
+        Drop sync credentials from password manager.
+      </message>
+      <message name="IDS_FLAGS_ENABLE_DROP_SYNC_CREDENTIAL_DESCRIPTION" desc="Description of the flag to enable drop sync credential">
+        If enabled, the password manager will not offer to save the credential used to sync.
+      </message>
       <message name="IDS_FLAGS_ENABLE_PASSWORD_GENERATION_NAME" desc="Name of the flag to enable password generation.">
         Enable password generation.
       </message>