Use BCP47 compliant format for locale representation

base/android/java/src/org/chromium/base/LocaleUtils.java

Index: base/android/java/src/org/chromium/base/LocaleUtils.java
diff --git a/base/android/java/src/org/chromium/base/LocaleUtils.java b/base/android/java/src/org/chromium/base/LocaleUtils.java
index 35d04a9b73b8e337f8469420e4141343810b2ef3..2be05fa0476a425d0bcb2ed8bdfd751bc84ab3db 100644
--- a/base/android/java/src/org/chromium/base/LocaleUtils.java
+++ b/base/android/java/src/org/chromium/base/LocaleUtils.java
@@ -4,9 +4,14 @@
 
 package org.chromium.base;
 
+import android.os.Build;
+
 import org.chromium.base.annotations.CalledByNative;
 
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.Locale;
+import java.util.Map;
 
 /**
  * This class provides the locale related methods.
@@ -18,36 +23,104 @@ public class LocaleUtils {
     private LocaleUtils() {
     }
 
+    // Android uses deprecated lanuages codes for Hebrew, Yiddish and Indonesian but
+    // Chromium uses the updated codes. Also, Android uses "tl" while Chromium uses "fil"
+    // for Tagalog/Filipino. So apply a mapping.
+    // See http://developer.android.com/reference/java/util/Locale.html
+    private static final Map<String, String> LANGUAGE_MAP;
+
+    static {
+        HashMap<String, String> map = new HashMap<>();
+        map.put("iw", "he"); // Hebrew
+        map.put("ji", "yi"); // Yiddish
+        map.put("in", "id"); // Indonesian
+        map.put("tl", "fil"); // Filipino
+        LANGUAGE_MAP = Collections.unmodifiableMap(map);
+    }
+
     /**
-     * @return The string for the given locale, translating Android deprecated language codes
-     *         into the modern ones used by Chromium.
+     * @return the string for the given locale with language and/or country code, translating

[ksk1, 2016/10/17 11:34:57]

"or" sounds strange 

[Yirui Huang, 2016/10/17 13:42:27]

Done.

+     *         Android deprecated language codes into the modern ones used by Chromium.
      */
     public static String getLocale(Locale locale) {
-        String language = getLanguage(locale);
+        String language = updateLanguageForChromium(locale.getLanguage());
         String country = locale.getCountry();
 
         return country.isEmpty() ? language : language + "-" + country;
     }
 
     /**
-     * @return The language for the given locale, translating Android deprecated languages codes
-     *         into modern ones used by Chromium.
+     * Handle the special cases in converting a language code/region code pair into an ISO-639-1
+     * language tag. When a language code used for Chromium is different from the language code
+     * in Android, update that language code for Chromium.
+     * @return a updated language code for Chromium if necessary.
+     **/
+    public static String updateLanguageForChromium(String language) {
+        String updatedLanguageCode = LANGUAGE_MAP.get(language);
+        return updatedLanguageCode == null ? language : updatedLanguageCode;
+    }
+
+    /**
+     * This function can be used for alternative of Locale.forLanguageTag before API Level 21.
+     * It creates Locale object from xx-XX style string where xx is language code and XX is
+     * a country code.
+     * @return the best representative locale with the language tag that has language and/or
+     *         country code.
+     */
+    @VisibleForTesting
+    static Locale forLanguageTagCompat(String languageTag) {

[Seigo Nonaka, 2016/10/17 11:30:46]

Please put public if this is accessed from test code.

[Yirui Huang, 2016/10/17 13:42:27]

Done.

+        if (languageTag.length() == 0) {
+            return new Locale("");
+        }
+        String[] tag = languageTag.split("-");
+        String language = tag[0];

[ksk1, 2016/10/17 11:21:16]

String language = updateLanguageForChromium(tag[0]);
And remove updateLanguageForChromium at l.81.

[Yirui Huang, 2016/10/17 13:42:27]

Done.

+        if (language.length() != 2 && language.length() != 3) {
+            return new Locale("");
+        }
+        if (tag.length == 1) {
+            language = updateLanguageForChromium(languageTag);
+            return new Locale(language);
+        }
+        String country = tag[1];
+        if (country.length() != 2 && country.length() != 3) {
+            return new Locale(language);
+        }
+        return new Locale(language, country);
+    }
+
+    /**
+     * It creates Locale object from xx-XX style string where xx is language code and XX is

[Seigo Nonaka, 2016/10/17 11:30:46]

"This function creates Locale object" or simply "Creates Locale object ..."

[Yirui Huang, 2016/10/17 13:42:27]

Done.

+     * a country code.
+     * @return the locale that best represents the language tag that has language and/or
+     *         country code.
+     */
+    public static Locale forLanguageTag(String languageTag) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            String[] tag = languageTag.split("-");
+            String updatedLanguage = updateLanguageForChromium(tag[0]);
+            if (tag.length == 1) {
+                return Locale.forLanguageTag(updatedLanguage);
+            }
+            return Locale.forLanguageTag(updatedLanguage + "-" + tag[1]);
+        }
+        return LocaleUtils.forLanguageTagCompat(languageTag);
+    }
+
+    /**
+     * @return a well-formed IETF BCP 47 language tag with language and country code that
+     *         represents this locale.
      */
-    public static String getLanguage(Locale locale) {
-        String language = locale.getLanguage();
-
-        // Android uses deprecated lanuages codes for Hebrew and Indonesian but Chromium uses the
-        // updated codes. Also, Android uses "tl" while Chromium uses "fil" for Tagalog/Filipino.
-        // So apply a mapping.
-        // See http://developer.android.com/reference/java/util/Locale.html
-        if ("iw".equals(language)) {
-            language = "he";
-        } else if ("in".equals(language)) {
-            language = "id";
-        } else if ("tl".equals(language)) {
-            language = "fil";
+    public static String toLanguageTag(Locale locale) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            String languageTag = locale.toLanguageTag();
+            String[] tag = languageTag.split("-");

[Seigo Nonaka, 2016/10/17 11:30:46]

Please do not split with hyphen here since there can be a script between
language and country.

How about this?

String languageForChrome = LANGUAGE_MAP.get(locale.getLanguage());
if (languageForChrome != null) {
  locale = new
Locale.Builder().setLocale(locale).setLanguage(languageForChrome).build();
}
return locale.toLangaugeTag();

[Yirui Huang, 2016/10/17 13:42:27]

Done.

+            String updatedLanguageTag = updateLanguageForChromium(tag[0]);
+            if (tag.length == 1) {
+                return updatedLanguageTag;
+            }
+            return updatedLanguageTag + "-" + tag[1];
         }
-        return language;
+        return getLocale(locale);
     }
 
     /**