Implement Linux media notifier.

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
===================================================================
--- content/browser/browser_main_loop.cc	(revision 124819)
+++ content/browser/browser_main_loop.cc	(working copy)
@@ -4,6 +4,8 @@
 
 #include "content/browser/browser_main_loop.h"
 
+#include <string>
+
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ -54,6 +56,14 @@
 #include "net/base/winsock_init.h"
 #endif
 
+#if defined(OS_LINUX)
+#include "content/browser/media_device_notifications_linux.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
@@ -204,7 +214,7 @@
   return g_current_browser_main_loop->audio_manager_.get();
 }
 
-// BrowserMainLoop construction / destructione =============================
+// BrowserMainLoop construction / destruction =============================
 
 BrowserMainLoop::BrowserMainLoop(const content::MainFunctionParams& parameters)
     : parameters_(parameters),
@@ -329,6 +339,8 @@
 
 #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
@@ -587,6 +599,17 @@
 void BrowserMainLoop::BrowserThreadsStarted() {
   // RDH needs the IO thread to be created.
   resource_dispatcher_host_.reset(new ResourceDispatcherHost());
+
+#if defined(OS_LINUX)
+  // MediaDeviceNotificationsLinux needs the File Thread.
+  const FilePath kDefaultMtabPath("/etc/mtab");

[vandebo (ex-Chrome), 2012/03/06 00:41:40]

Random thought - does this work on CrOS?  It should, but crazy stuff might be
going on.

[Lei Zhang, 2012/03/06 19:00:25]

It should based on our observations on a Chromebook in dev mode.

+  media_device_notifications_linux_ =
+      new MediaDeviceNotificationsLinux(kDefaultMtabPath);
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&MediaDeviceNotificationsLinux::InitOnFileThread,
+                 media_device_notifications_linux_.get()));
+#endif
 }
 
 void BrowserMainLoop::InitializeToolkit() {