Implement a salt for MediaSource IDs that can be cleared by a user.

content/browser/renderer_host/media/device_request_message_filter.cc

Index: content/browser/renderer_host/media/device_request_message_filter.cc
diff --git a/content/browser/renderer_host/media/device_request_message_filter.cc b/content/browser/renderer_host/media/device_request_message_filter.cc
index 60729cae4c984fd450a103b5e434fc0a9f48718c..b5bdcb5a2f25fc950303831f956021a98a448843 100644
--- a/content/browser/renderer_host/media/device_request_message_filter.cc
+++ b/content/browser/renderer_host/media/device_request_message_filter.cc
@@ -153,12 +153,14 @@ void DeviceRequestMessageFilter::OnGetSources(int request_id,
                                               const GURL& security_origin) {
   // Make request to get audio devices.
   const std::string& audio_label = media_stream_manager_->EnumerateDevices(
-      this, -1, -1, -1, MEDIA_DEVICE_AUDIO_CAPTURE, security_origin);
+      this, -1, -1, resource_context_, -1, MEDIA_DEVICE_AUDIO_CAPTURE,
+      security_origin);
   DCHECK(!audio_label.empty());
 
   // Make request for video devices.
   const std::string& video_label = media_stream_manager_->EnumerateDevices(
-      this, -1, -1, -1, MEDIA_DEVICE_VIDEO_CAPTURE, security_origin);
+      this, -1, -1, resource_context_, -1, MEDIA_DEVICE_VIDEO_CAPTURE,
+      security_origin);
   DCHECK(!video_label.empty());
 
   requests_.push_back(DeviceRequest(