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

content/browser/media/media_devices_monitor.cc

Index: content/browser/media/media_devices_monitor.cc
diff --git a/content/browser/media_devices_monitor.cc b/content/browser/media/media_devices_monitor.cc
similarity index 81%
rename from content/browser/media_devices_monitor.cc
rename to content/browser/media/media_devices_monitor.cc
index 72c3b4b1cefcc1b7c9a4180d63abe780212cde5d..8f239a9b10aa4f03e39f0aa72f7e4b21335c0024 100644
--- a/content/browser/media_devices_monitor.cc
+++ b/content/browser/media/media_devices_monitor.cc
@@ -12,8 +12,10 @@ namespace content {
 namespace {
 void EnsureMonitorCaptureDevicesInternal(
     MediaStreamManager* media_stream_manager) {
+  // TODO(perkj): The argument list suggests that this is the wrong design. Can
+  // we add a separate method for device monitoring?
   media_stream_manager->EnumerateDevices(
-      NULL, -1, -1, -1, MEDIA_DEVICE_AUDIO_CAPTURE, GURL());
+      NULL, -1, -1, NULL, -1, MEDIA_DEVICE_AUDIO_CAPTURE, GURL());
 }
 }