Make default media device ID salts random by default

chrome/browser/profiles/profile_io_data.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.
 
 #ifndef CHROME_BROWSER_PROFILES_PROFILE_IO_DATA_H_
 #define CHROME_BROWSER_PROFILES_PROFILE_IO_DATA_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 167 matching lines @@
   }
 
   BooleanPrefMember* signin_allowed() const {
     return &signin_allowed_;
   }
 
   IntegerPrefMember* network_prediction_options() const {
     return &network_prediction_options_;
   }
 
+  bool HasMediaDeviceIDSalt() const {
+    return media_device_id_salt_.get() != nullptr;
+  }
+
   content::ResourceContext::SaltCallback GetMediaDeviceIDSalt() const;
 
   DevToolsNetworkControllerHandle* network_controller_handle() const {
     return &network_controller_handle_;
   }
 
   net::TransportSecurityState* transport_security_state() const {
     return transport_security_state_.get();
   }
 
@@ skipping 419 matching lines @@
   mutable std::unique_ptr<certificate_transparency::TreeStateTracker>
       ct_tree_tracker_;
   mutable base::Closure ct_tree_tracker_unregistration_;
 
   const Profile::ProfileType profile_type_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileIOData);
 };
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILE_IO_DATA_H_