[Hotword] Uninstall and reinstall the extension upon language change.

chrome/common/pref_names.cc

 // Copyright (c) 2012 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/common/pref_names.h"
 
 #include "base/basictypes.h"
 #include "chrome/common/pref_font_webkit_names.h"
 
 namespace prefs {
@@ skipping 1837 matching lines @@
 const char kVideoCaptureAllowedUrls[] = "hardware.video_capture_allowed_urls";
 
 // A boolean pref that controls the enabled-state of hotword search voice
 // trigger.
 const char kHotwordSearchEnabled[] = "hotword.search_enabled_2";
 
 // A boolean pref that controls whether the sound of "Ok, Google" plus a few
 // seconds of audio data before is sent back to improve voice search.
 const char kHotwordAudioLoggingEnabled[] = "hotword.audio_logging_enabled";
 
+// A string holding the locale information under which Hotword was installed.
+// It is used for comparison since the hotword voice search trigger must be
+// reinstalled to handle a new language.
+const char kHotwordPreviousLanguage[] = "hotword.previous_language";
+
 #if defined(OS_ANDROID)
 // Boolean that controls the global enabled-state of protected media identifier.
 const char kProtectedMediaIdentifierEnabled[] =
     "protected_media_identifier.enabled";
 #endif
 
 #if defined(OS_CHROMEOS)
 // Dictionary for transient storage of settings that should go into device
 // settings storage before owner has been assigned.
 const char kDeviceSettingsCache[] = "signed_settings_cache";
@@ skipping 513 matching lines @@
 // "mapped_title" entries, detailing the bookmark target URL (if any), the title
 // given by the PartnerBookmarksProvider and either the user-visible renamed
 // title or an empty string if the bookmark node was removed.
 const char kPartnerBookmarkMappings[] = "partnerbookmarks.mappings";
 #endif
 
 // Whether DNS Quick Check is disabled in proxy resolution.
 const char kQuickCheckEnabled[] = "proxy.quick_check_enabled";
 
 }  // namespace prefs