linux: Add some font-family-related FontRenderParams tests.

ui/gfx/test/fontconfig_util_linux.h

 // Copyright 2014 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 UI_GFX_TEST_FONTCONFIG_UTIL_LINUX_H_
 #define UI_GFX_TEST_FONTCONFIG_UTIL_LINUX_H_
 
 #include <string>
 
 #include "base/files/file_path.h"
@@ skipping 36 matching lines @@
 std::string CreateFontconfigEditStanza(const std::string& name,
                                        const std::string& type,
                                        const std::string& value);
 
 // Returns a Fontconfig <test> stanza.
 std::string CreateFontconfigTestStanza(const std::string& name,
                                        const std::string& op,
                                        const std::string& type,
                                        const std::string& value);
 
+// Returns a Fontconfig <alias> stanza.
+std::string CreateFontconfigAliasStanza(const std::string& original_family,
+                                        const std::string& preferred_family);
+
 }  // namespace gfx
 
 #endif  // UI_GFX_TEST_FONTCONFIG_UTIL_LINUX_H_