Set User-Agent and Accept-Language request headers for PWS requests

chrome/browser/android/preferences/pref_service_bridge.cc

 // 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.
 
 #include "chrome/browser/android/preferences/pref_service_bridge.h"
 
 #include <jni.h>
 #include <stddef.h>
 
 #include <memory>
@@ skipping 1078 matching lines @@
       env, GetPrefService()->GetString(
                prefs::kSupervisedUserSecondCustodianProfileImageURL));
 }
 
 // static
 bool PrefServiceBridge::RegisterPrefServiceBridge(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 // static
+// This logic should be kept in sync with prependToAcceptLanguagesIfNecessary in
+// chrome/android/java/src/org/chromium/chrome/browser/
+//     physicalweb/PwsClientImpl.java
 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::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);
     }
     parts.push_back(*accept_languages);
     *accept_languages = base::JoinString(parts, ",");
   }
 }
 
 // static
 std::string PrefServiceBridge::GetAndroidPermissionForContentSetting(
     ContentSettingsType content_type) {
   JNIEnv* env = AttachCurrentThread();
   base::android::ScopedJavaLocalRef<jstring> android_permission =
       Java_PrefServiceBridge_getAndroidPermissionForContentSetting(
           env, content_type);
   if (android_permission.is_null())
     return std::string();
 
   return ConvertJavaStringToUTF8(android_permission);
 }
 
 static void SetSupervisedUserId(JNIEnv* env,
                                 const JavaParamRef<jobject>& obj,
                                 const JavaParamRef<jstring>& pref) {
   GetPrefService()->SetString(prefs::kSupervisedUserId,
                               ConvertJavaStringToUTF8(env, pref));
 }