Revert of Make default media device ID salts random by default

chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.h

Index: chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.h
diff --git a/chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.h b/chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.h
index e10607993d80d1fc8898013726e1c2f2447d093e..a90c4aa39eeb933d943e713536249378cc5f4a70 100644
--- a/chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.h
+++ b/chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.h
@@ -6,8 +6,6 @@
 #define CHROME_BROWSER_EXTENSIONS_API_WEBRTC_AUDIO_PRIVATE_WEBRTC_AUDIO_PRIVATE_API_H_
 
 #include <stddef.h>
-
-#include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ -98,10 +96,10 @@
 
   // Callable from any thread. Must previously have called
   // |InitDeviceIDSalt()|.
-  std::string device_id_salt() const;
-
- private:
-  std::string device_id_salt_;
+  const content::ResourceContext::SaltCallback& device_id_salt() const;
+
+ private:
+  content::ResourceContext::SaltCallback device_id_salt_;
 
   DISALLOW_COPY_AND_ASSIGN(WebrtcAudioPrivateFunction);
 };