Create TetherService, a TetherAllowed pref, and use DependencyManager for RegisterProfilePrefs call…

chrome/common/pref_names.h

 // 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.
 
 // Constants for the names of various preferences, for easier changing.
 
 #ifndef CHROME_COMMON_PREF_NAMES_H_
 #define CHROME_COMMON_PREF_NAMES_H_
 
 #include <stddef.h>
@@ skipping 307 matching lines @@
 extern const char kEolStatus[];
 extern const char kEolNotificationDismissed[];
 extern const char kPinUnlockFeatureNotificationShown[];
 extern const char kFingerprintUnlockFeatureNotificationShown[];
 extern const char kQuickUnlockModeWhitelist[];
 extern const char kQuickUnlockTimeout[];
 extern const char kPinUnlockMinimumLength[];
 extern const char kPinUnlockMaximumLength[];
 extern const char kPinUnlockWeakPinsAllowed[];
 extern const char kEnableQuickUnlockFingerprint[];
+extern const char kInstantTetheringAllowed[];
 #endif  // defined(OS_CHROMEOS)
 extern const char kShowHomeButton[];
 extern const char kSpeechRecognitionFilterProfanities[];
 extern const char kSavingBrowserHistoryDisabled[];
 extern const char kAllowDeletingBrowserHistory[];
 #if !defined(OS_ANDROID) && !defined(OS_IOS)
 extern const char kMdHistoryMenuPromoShown[];
 #endif
 extern const char kForceGoogleSafeSearch[];
 extern const char kForceYouTubeRestrict[];
@@ skipping 572 matching lines @@
 extern const char kHistoryPageIOSPromoDismissed[];
 #endif
 
 extern const char kSettingsResetPromptPromptWave[];
 extern const char kSettingsResetPromptLastTriggeredForDefaultSearch[];
 extern const char kSettingsResetPromptLastTriggeredForStartupUrls[];
 extern const char kSettingsResetPromptLastTriggeredForHomepage[];
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_