Move GnomeKeyringLoader to components/os_crypt

components/os_crypt/keyring_util_linux.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_OS_CRYPT_KEYRING_UTIL_LINUX_H_
+#define COMPONENTS_OS_CRYPT_KEYRING_UTIL_LINUX_H_
+
+// libgnome-keyring has been deprecated in favor of libsecret.
+// See: https://mail.gnome.org/archives/commits-list/2013-October/msg08876.html
+//
+// The define below turns off the deprecations, in order to avoid build
+// failures with Gnome 3.12. When we move to libsecret, the define can be
+// removed, together with the include below it.
+//
+// The porting is tracked in http://crbug.com/355223
+#define GNOME_KEYRING_DEPRECATED
+#define GNOME_KEYRING_DEPRECATED_FOR(x)
+#include <gnome-keyring.h>
+
+#include "base/macros.h"
+
+// Many of the gnome_keyring_* functions use variable arguments, which makes
+// them difficult if not impossible to truly wrap in C. Therefore, we use
+// appropriately-typed function pointers and scoping to make the fact that we
+// might be dynamically loading the library almost invisible. As a bonus, we
+// also get a simple way to mock the library for testing. Classes that inherit
+// from GnomeKeyringLoader will use its versions of the gnome_keyring_*
+// functions. Note that it has only static fields.
+class GnomeKeyringLoader {
+ protected:
+  static bool LoadGnomeKeyring();
+
+  // Declare the actual function pointers that we'll use in client code.
+  static decltype(&::gnome_keyring_is_available) gnome_keyring_is_available_ptr;
+  static decltype(
+      &::gnome_keyring_store_password) gnome_keyring_store_password_ptr;
+  static decltype(
+      &::gnome_keyring_delete_password) gnome_keyring_delete_password_ptr;
+  static decltype(&::gnome_keyring_find_items) gnome_keyring_find_items_ptr;
+  static decltype(
+      &::gnome_keyring_result_to_message) gnome_keyring_result_to_message_ptr;
+  static decltype(&::gnome_keyring_attribute_list_free)
+      gnome_keyring_attribute_list_free_ptr;
+  static decltype(
+      &::gnome_keyring_attribute_list_new) gnome_keyring_attribute_list_new_ptr;
+  static decltype(&::gnome_keyring_attribute_list_append_string)
+      gnome_keyring_attribute_list_append_string_ptr;
+  static decltype(&::gnome_keyring_attribute_list_append_uint32)
+      gnome_keyring_attribute_list_append_uint32_ptr;
+  // We also use gnome_keyring_attribute_list_index(), which is a macro and
+  // can't be referenced.
+
+  // Set to true if LoadGnomeKeyring() has already succeeded.
+  static bool keyring_loaded;
+
+ private:
+  struct FunctionInfo {
+    const char* name;
+    void** pointer;
+  };
+
+  // Make it easy to initialize the function pointers in LoadGnomeKeyring().
+  static const FunctionInfo functions[];
+};
+
+#endif  // COMPONENTS_OS_CRYPT_KEYRING_UTIL_LINUX_H_