Convert some audio code to OnceCallback.

content/browser/media/media_devices_permission_checker.h

Index: content/browser/media/media_devices_permission_checker.h
diff --git a/content/browser/media/media_devices_permission_checker.h b/content/browser/media/media_devices_permission_checker.h
index 3eb22554b219eeb3c2b7a518a48802abf46f2bb1..a27947cd158fc7fd49d071594df9467e0fb7567c 100644
--- a/content/browser/media/media_devices_permission_checker.h
+++ b/content/browser/media/media_devices_permission_checker.h
@@ -47,7 +47,7 @@ class CONTENT_EXPORT MediaDevicesPermissionChecker {
                        int render_process_id,
                        int render_frame_id,
                        const url::Origin& security_origin,
-                       const base::Callback<void(bool)>& callback) const;
+                       base::OnceCallback<void(bool)> callback) const;
 
   // Checks if the origin |security_origin| associated to a render frame
   // identified by |render_process_id| and |render_frame_id| is allowed to
@@ -63,7 +63,7 @@ class CONTENT_EXPORT MediaDevicesPermissionChecker {
       int render_process_id,
       int render_frame_id,
       const url::Origin& security_origin,
-      const base::Callback<void(const MediaDevicesManager::BoolDeviceTypes&)>&
+      base::OnceCallback<void(const MediaDevicesManager::BoolDeviceTypes&)>
           callback) const;
 
  private: