Fallback Font Cache and Character Hinting for VRShell

chrome/browser/android/vr_shell/font_fallback.h

+// Copyright 2017 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 CHROME_BROWSER_ANDROID_VR_SHELL_FONT_FALLBACK_H_
+#define CHROME_BROWSER_ANDROID_VR_SHELL_FONT_FALLBACK_H_
+
+#include <string>
+
+#include "third_party/icu/source/common/unicode/uchar.h"
+
+namespace gfx {
+class Font;
+}  // namespace gfx
+
+namespace vr_shell {
+
+// Return a font name which provides a glyph for the Unicode code point
+// specified by character.
+//   default_font: The main font for which fallbacks are required
+//   c: a UTF-32 code point
+//   preferred_locale: preferred locale identifier (if any) for |c|
+//                     (e.g. "en", "ja", "zh-CN")
+//
+// Returns: the font name. The value is empty if the request could not be
+// satisfied or if the provided default font supports it.
+std::string GetFallbackFontNameForChar(const gfx::Font& default_font,
+                                       UChar32 c,
+                                       const std::string& preferred_locale);
+
+}  // namespace vr_shell
+
+#endif  // CHROME_BROWSER_ANDROID_VR_SHELL_FONT_FALLBACK_H_