Add Media device notification to SystemMonitor and Mac impl

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index a9c24e083d7427b5decd6a1de8310814080523eb..6c59b06b8136cd4b8724e03530c54a8fe50446c2 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -53,6 +53,10 @@
 #include "net/base/winsock_init.h"
 #endif
 
+#if defined(OS_MACOSX)
+#include "content/browser/mac/media_device_notifications.h"
+#endif
+
 #if defined(OS_LINUX) || defined(OS_OPENBSD)
 #include <glib-object.h>
 #endif
@@ -329,6 +333,8 @@ void BrowserMainLoop::MainMessageLoopStart() {
 
 #if defined(OS_WIN)
   system_message_window_.reset(new SystemMessageWindowWin);
+#elif defined(OS_MACOSX)
+  StartMediaDeviceNotifications();
 #endif
 
   // Prior to any processing happening on the io thread, we create the