[Password Manager] Setup experiment to restrict autofilling of sync credential

components/password_manager/core/browser/password_manager_client.h

Index: components/password_manager/core/browser/password_manager_client.h
diff --git a/components/password_manager/core/browser/password_manager_client.h b/components/password_manager/core/browser/password_manager_client.h
index 4607800d7357cba447fc5773ecca73a2414f282b..99f1282258cbf8a7f39a5c327fab276a2ea89664 100644
--- a/components/password_manager/core/browser/password_manager_client.h
+++ b/components/password_manager/core/browser/password_manager_client.h
@@ -35,11 +35,19 @@ class PasswordManagerClient {
   // always returns true.
   virtual bool IsPasswordManagerEnabledForCurrentPage() const;
 
+  // Return true if |form| should not be available for autofill.
+  virtual bool ShouldFilterAutofillResult(
+      const autofill::PasswordForm& form) = 0;
+
   // Returns true if |username| and |origin| correspond to the account which is
   // syncing.
   virtual bool IsSyncAccountCredential(
       const std::string& username, const std::string& origin) const = 0;
 
+  // Called when all autofill results have been computed. Client can use
+  // this signal to report statistics. Default implementation is a noop.
+  virtual void AutofillResultsComputed() {}
+
   // Informs the embedder of a password form that can be saved if the user
   // allows it. The embedder is not required to prompt the user if it decides
   // that this form doesn't need to be saved.