Allow offering to save google passwords.

Goes around upstream check for gaia credential page and empty primary
account in the browser.

Fixes brave/brave-browser#17595
Fixes brave/brave-browser#16926

chromium_src/components/password_manager/core/browser/sync_credentials_filter.cc

@@ -0,0 +1,22 @@
+/* Copyright (c) 2021 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "components/password_manager/core/browser/sync_credentials_filter.h"
+
+#define ShouldSave ShouldSave_ChromiumImpl
+#include "../../../../../../components/password_manager/core/browser/sync_credentials_filter.cc"
+#undef ShouldSave
+
+namespace password_manager {
+
+bool SyncCredentialsFilter::ShouldSave(const PasswordForm& form) const {
+  bool should_save = ShouldSave_ChromiumImpl(form);
+  if (!should_save && sync_util::IsGaiaCredentialPage(form.signon_realm)) {
+    return true;
+  }
+  return should_save;
+}
+
+}  // namespace password_manager

chromium_src/components/password_manager/core/browser/sync_credentials_filter.h

@@ -0,0 +1,19 @@
+/* Copyright (c) 2021 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BRAVE_CHROMIUM_SRC_COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SYNC_CREDENTIALS_FILTER_H_
+#define BRAVE_CHROMIUM_SRC_COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SYNC_CREDENTIALS_FILTER_H_
+
+#include "components/password_manager/core/browser/credentials_filter.h"
+
+#define ShouldSave                                         \
+  ShouldSave_ChromiumImpl(const PasswordForm& form) const; \
+  bool ShouldSave
+
+#include "../../../../../../components/password_manager/core/browser/sync_credentials_filter.h"
+
+#undef ShouldSave
+
+#endif  // BRAVE_CHROMIUM_SRC_COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SYNC_CREDENTIALS_FILTER_H_