[ios] Adds configuration helper files for voice search.

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"
+
+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.
+class SpeechInputLocaleConfigImpl : public SpeechInputLocaleConfig {
+ public:
+  // Singleton getter for subclass.
+  static SpeechInputLocaleConfigImpl* GetInstance();
+
+  // Returns the available locale that matches |locale_code|.  Defaults to en-US
+  // if a matching locale is not found.
+  SpeechInputLocale GetMatchingLocale(const std::string& locale_code) const;
+
+  // SpeechInputLocaleConfig:
+  SpeechInputLocale GetDefaultLocale() const override;
+  const std::vector<SpeechInputLocale>& GetAvailableLocales() const override;
+  SpeechInputLocale GetLocaleForCode(
+      const std::string& locale_code) const override;
+  const std::vector<std::string>& GetTextToSpeechLanguages() const override;
+  bool IsTextToSpeechEnabledForCode(
+      const std::string& locale_code) const override;
+
+ protected:
+  // The constructor is protected, as the object must be referenced via
+  // SpeechInputLocaleConfig's singleton getter.
+  SpeechInputLocaleConfigImpl();
+  ~SpeechInputLocaleConfigImpl() override;
+
+ private:
+  // Returns a canonical locale code created from combining the UI language
+  // preference from NSLocale's |+preferredLanguages| and the country code from
+  // the device's locale.
+  std::string GetDefaultLocaleCode() const;
+
+  // Populates |available_locales_| using S3Kit's language manager.
+  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>;
+
+  // 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_