Factor out authorization from AudioRendererHost.

content/public/browser/media_device_id.h

 // Copyright 2013 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.
 //
 // Media device IDs come in two flavors: The machine-wide unique ID of
 // the device, which is what we use on the browser side, and one-way
 // hashes over the unique ID and a security origin, which we provide
 // to code on the renderer side as per-security-origin IDs.
 
 #ifndef CONTENT_PUBLIC_BROWSER_MEDIA_DEVICE_ID_H_
@@ skipping 22 matching lines @@
     const url::Origin& security_origin,
     const std::string& device_guid,
     const std::string& raw_unique_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);
 
+CONTENT_EXPORT bool IsValidDeviceId(const std::string& device_id);
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_MEDIA_DEVICE_ID_H_