Forward declare test class as friend of SpeechInputLocaleConfigImpl.

ios/chrome/browser/voice/speech_input_locale_config_impl.h

 // Copyright 2016 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.
 
 #ifndef IOS_CHROME_BROWSER_VOICE_SPEECH_INPUT_LOCALE_CONFIG_IMPL_H_
 #define IOS_CHROME_BROWSER_VOICE_SPEECH_INPUT_LOCALE_CONFIG_IMPL_H_
 
 #include <map>
 
 #include "base/memory/singleton.h"
 #include "ios/chrome/browser/voice/speech_input_locale_config.h"
 
+class SpeechInputLocaleConfigImplTest;
+
 namespace base {
 template <typename T>
 struct DefaultSingletonTraits;
 }  // namespace base
 
 namespace voice {
 
 // A concrete implementation of SpeechInputLocaleConfig that uses the available
 // language list from S3Kit and the speech input locale matching from
 // SpeechInputLocaleMatches.plist.
@@ skipping 31 matching lines @@
   void InitializeAvailableLocales();
 
   // Adds local matching data from speech_input_matches.plist into
   // |locale_indices_for_codes_|.
   void InitializeLocaleMatches();
 
   // Populates |text_to_speech_languages_| with the available locales.
   void InitializeTextToSpeechLangauges();
 
   friend struct base::DefaultSingletonTraits<SpeechInputLocaleConfigImpl>;
+  friend class ::SpeechInputLocaleConfigImplTest;
 
   // The list of available speech input locales.
   std::vector<SpeechInputLocale> available_locales_;
   // A map storing canonical locale codes with the index of their associated
   // InputLocale within |available_locales_|.
   std::map<std::string, size_t> locale_indices_for_codes_;
   // A map storing the language portions of locale codes with the index of their
   // associated InputLocale within |available_locales_|.
   std::map<std::string, size_t> default_locale_indices_for_languages_;
   // The languages available for Text To Speech search results.
   std::vector<std::string> text_to_speech_languages_;
 
   DISALLOW_COPY_AND_ASSIGN(SpeechInputLocaleConfigImpl);
 };
 
 }  // namespace voice
 
 #endif  // IOS_CHROME_BROWSER_VOICE_SPEECH_INPUT_LOCALE_CONFIG_IMPL_H_