Added translation policy API.

ios/web_view/internal/translate/cwv_translation_language.mm

 // 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.
 
 #import "ios/web_view/internal/translate/cwv_translation_language_internal.h"
 
 #include "base/strings/string16.h"
 #include "base/strings/sys_string_conversions.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 @implementation CWVTranslationLanguage
 
 @synthesize languageCode = _languageCode;
 @synthesize languageName = _languageName;
 
 - (instancetype)initWithLanguageCode:(const std::string&)languageCode
                         languageName:(const base::string16&)languageName {
   self = [super init];
   if (self) {
     _languageCode = base::SysUTF8ToNSString(languageCode);
     _languageName = base::SysUTF16ToNSString(languageName);
   }
   return self;
 }
 
+- (NSString*)description {
+  return [NSString stringWithFormat:@"%@ name:%@ code:%@", [super description],
+                                    _languageName, _languageCode];
+}
+
 @end