Make default media device ID salts random by default

content/public/browser/media_device_id.h

Index: content/public/browser/media_device_id.h
diff --git a/content/public/browser/media_device_id.h b/content/public/browser/media_device_id.h
index 579d995f5b4387384726c05eb056708497b1b510..a08320ca2721d78fe2057c5c9be886975a8b8914 100644
--- a/content/public/browser/media_device_id.h
+++ b/content/public/browser/media_device_id.h
@@ -22,24 +22,23 @@ namespace content {
 // Generates a one-way hash of a device's unique ID usable by one
 // particular security origin.
 CONTENT_EXPORT std::string GetHMACForMediaDeviceID(
-    const ResourceContext::SaltCallback& sc,
+    const std::string& salt,
     const url::Origin& security_origin,
     const std::string& raw_unique_id);
 
 // Convenience method to check if |device_guid| is an HMAC of
 // |raw_device_id| for |security_origin|.
 CONTENT_EXPORT bool DoesMediaDeviceIDMatchHMAC(
-    const ResourceContext::SaltCallback& sc,
+    const std::string& salt,
     const url::Origin& security_origin,
     const std::string& device_guid,
     const std::string& raw_unique_id);
 
-CONTENT_EXPORT bool GetMediaDeviceIDForHMAC(
-    MediaStreamType stream_type,
-    const ResourceContext::SaltCallback& rc,
-    const url::Origin& security_origin,
-    const std::string& source_id,
-    std::string* device_id);
+CONTENT_EXPORT bool GetMediaDeviceIDForHMAC(MediaStreamType stream_type,
+                                            const std::string& salt,
+                                            const url::Origin& security_origin,
+                                            const std::string& source_id,
+                                            std::string* device_id);
 
 }  // namespace content