Support multiple locales string for accept language list

chrome/browser/android/preferences/pref_service_bridge.cc

Index: chrome/browser/android/preferences/pref_service_bridge.cc
diff --git a/chrome/browser/android/preferences/pref_service_bridge.cc b/chrome/browser/android/preferences/pref_service_bridge.cc
index 4ddaa35f57066297b40d4ccac5e6c67181670552..c86925d2a649b3df3652b16c87903ccd2fa0b35e 100644
--- a/chrome/browser/android/preferences/pref_service_bridge.cc
+++ b/chrome/browser/android/preferences/pref_service_bridge.cc
@@ -1063,7 +1063,6 @@ static void ResetAcceptLanguages(JNIEnv* env,
                                  const JavaParamRef<jstring>& default_locale) {
   std::string accept_languages(l10n_util::GetStringUTF8(IDS_ACCEPT_LANGUAGES));
   std::string locale_string(ConvertJavaStringToUTF8(env, default_locale));
-
   PrefServiceBridge::PrependToAcceptLanguagesIfNecessary(locale_string,
                                                          &accept_languages);
   GetPrefService()->SetString(prefs::kAcceptLanguages, accept_languages);
@@ -1147,39 +1146,62 @@ bool PrefServiceBridge::RegisterPrefServiceBridge(JNIEnv* env) {
 void PrefServiceBridge::PrependToAcceptLanguagesIfNecessary(
     const std::string& locale,
     std::string* accept_languages) {
-  if (locale.size() != 5u || locale[2] != '_')  // not well-formed
-    return;
-
-  std::string language(locale.substr(0, 2));
-  std::string region(locale.substr(3, 2));
-
-  // Java mostly follows ISO-639-1 and ICU, except for the following three.
-  // See documentation on java.util.Locale constructor for more.
-  if (language == "iw") {
-    language = "he";
-  } else if (language == "ji") {
-    language = "yi";
-  } else if (language == "in") {
-    language = "id";
+  std::vector<std::string> lans;

[Seigo Nonaka, 2016/10/05 07:15:41]

probably, languages or langs are preferred.

[Yirui Huang, 2016/10/06 01:17:59]

Done.

+  std::string languages_to_check = locale;
+  // Check see if it is a Locale List or single Locale
+  if (languages_to_check.length() > 5) {

[Seigo Nonaka, 2016/10/05 07:15:41]

Looks like this is not a good condition for checking the input is locale list or
not.
For example, "en,ja" is 5-length string but it is a list of the locales.

[Yirui Huang, 2016/10/06 01:17:59]

Done.

+    while (languages_to_check.find(",") != std::string::npos) {
+      std::size_t bfound = 0;
+      std::size_t efound = languages_to_check.find(",");
+      lans.push_back(languages_to_check.substr(bfound, efound));
+      bfound = efound + 1;
+      languages_to_check = languages_to_check.substr(bfound);

[Seigo Nonaka, 2016/10/05 07:15:41]

Since languages_to_check is a std::string, you create new std::string object for
each while loop.
Instead how about using 2nd argument of the std::string::find method?
http://www.cplusplus.com/reference/string/string/find/

[Yirui Huang, 2016/10/06 01:17:59]

Done.

+      // Check the last element
+      if (languages_to_check.length() <= 5) {

[Seigo Nonaka, 2016/10/05 07:15:41]

Similarly, languages_to_check can be still list even if it is less than 5 chars,
e.g. "en,ja"

[Yirui Huang, 2016/10/06 01:17:59]

Done.

+        lans.push_back(languages_to_check);
+        break;
+      }
+    }
+  } else {
+    lans.push_back(languages_to_check);
   }
 
-  std::string language_region(language + "-" + region);
-
-  if (accept_languages->find(language_region) == std::string::npos) {
-    std::vector<std::string> parts;
-    parts.push_back(language_region);
-    // If language is not in the accept languages list, also add language code.
-    // This will work with the IDS_ACCEPT_LANGUAGE localized strings bundled
-    // with Chrome but may fail on arbitrary lists of language tags due to
-    // differences in case and whitespace.
-    if (accept_languages->find(language + ",") == std::string::npos &&
-        !std::equal(language.rbegin(), language.rend(),
-                    accept_languages->rbegin())) {
-      parts.push_back(language);
+  std::vector<std::string> parts;
+  for (std::size_t i = 0; i < lans.size(); i++) {
+    if (lans[i].size() != 5u || lans[i][2] != '_')  // not well-formed
+      continue;
+    std::string language(lans[i].substr(0, 2));
+    std::string region(lans[i].substr(3, 2));
+
+    // Java mostly follows ISO-639-1 and ICU, except for the following three.
+    // See documentation on java.util.Locale constructor for more.
+    if (language == "iw") {
+      language = "he";
+    } else if (language == "ji") {
+      language = "yi";
+    } else if (language == "in") {
+      language = "id";
+    }
+
+    std::string language_region(language + "-" + region);
+
+    if (accept_languages->find(language_region) == std::string::npos) {
+      parts.push_back(language_region);
+      // If language is not in the accept languages list, also add language
+      // code.
+      // This will work with the IDS_ACCEPT_LANGUAGE localized strings bundled
+      // with Chrome but may fail on arbitrary lists of language tags due to
+      // differences in case and whitespace.
+      if ((accept_languages->find(language) == std::string::npos ||
+           accept_languages->find(language + ",") == std::string::npos) &&
+          !std::equal(language.rbegin(), language.rend(),
+                      accept_languages->rbegin())) {
+        parts.push_back(language);
+      }
     }
-    parts.push_back(*accept_languages);
-    *accept_languages = base::JoinString(parts, ",");
   }
+  parts.push_back(*accept_languages);
+  *accept_languages = base::JoinString(parts, ",");
 }
 
 // static