Improve getFallbackFamily() for Unified Han Ideographs on Windows

Source/platform/fonts/win/FontFallbackWinTest.cpp

+// Copyright 2015 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.
+
+#include "config.h"
+#include "platform/fonts/win/FontFallbackWin.h"
+
+#include <gtest/gtest.h>
+
+namespace blink {
+
+TEST(FontFallbackWinTest, scriptCodeForUnifiedHanFromLocaleTest)
+{
+    EXPECT_EQ(USCRIPT_HIRAGANA, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("ja", "JP")));
+    EXPECT_EQ(USCRIPT_HANGUL, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("ko", "KR")));
+    EXPECT_EQ(USCRIPT_TRADITIONAL_HAN, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("zh", "TW")));
+    EXPECT_EQ(USCRIPT_SIMPLIFIED_HAN, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("zh", "CN")));
+
+    EXPECT_EQ(USCRIPT_TRADITIONAL_HAN, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("zh", "HK")));
+
+    // icu::Locale::getDefault() returns other combinations if, for instnace,
+    // English Windows with the display language set to Japanese.
+    EXPECT_EQ(USCRIPT_HIRAGANA, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("ja")));
+    EXPECT_EQ(USCRIPT_HIRAGANA, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("ja", "US")));
+    EXPECT_EQ(USCRIPT_HANGUL, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("ko")));
+    EXPECT_EQ(USCRIPT_HANGUL, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("ko", "US")));
+    EXPECT_EQ(USCRIPT_TRADITIONAL_HAN, scriptCodeForUnifiedHanFromLocale(
+        icu::Locale("zh", "hant")));
+}
+
+} // namespace blink