Add Media device notification to SystemMonitor and Mac impl

base/system_monitor/system_monitor.h

Index: base/system_monitor/system_monitor.h
diff --git a/base/system_monitor/system_monitor.h b/base/system_monitor/system_monitor.h
index 7684523616e0bd787e3a30f5ded9c40e1f7b5371..d381268a8415497ed770f86ac9209ab98dbbd3f8 100644
--- a/base/system_monitor/system_monitor.h
+++ b/base/system_monitor/system_monitor.h
@@ -8,6 +8,7 @@
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
+#include "base/file_path.h"

[tpayne, 2012/02/08 16:20:30]

I thought forward declarations are preferred over including the .h file

[vandebo (ex-Chrome), 2012/02/08 18:37:01]

Right, but the bind code, which is used by the observer code, needs the full
definition.

 #include "build/build_config.h"
 
 // Windows HiRes timers drain the battery faster so we need to know the battery
@@ -95,6 +96,14 @@ class BASE_EXPORT SystemMonitor {
     // Notification that the devices connected to the system have changed.
     virtual void OnDevicesChanged() {}
 
+    // When a media device is attached or detached, we also fire one of these
+    // two events.
+    // TODO(vandebo) Pass an appropriate device identifier instead of FilePath.
+    virtual void OnMediaDeviceAttached(const std::string& name,
+                                       const FilePath& path) {}
+
+    virtual void OnMediaDeviceDetached(const std::string& name) {}
+
    protected:
     virtual ~DevicesChangedObserver() {}
   };
@@ -123,6 +132,9 @@ class BASE_EXPORT SystemMonitor {
 
   // Cross-platform handling of a device change event.
   void ProcessDevicesChanged();
+  void ProcessMediaDeviceAttached(const std::string& name,
+                                  const FilePath& path);
+  void ProcessMediaDeviceDetached(const std::string& name);
 
  private:
 #if defined(OS_MACOSX)
@@ -141,6 +153,8 @@ class BASE_EXPORT SystemMonitor {
 
   // Functions to trigger notifications.
   void NotifyDevicesChanged();
+  void NotifyMediaDeviceAttached(const std::string& name, const FilePath& path);
+  void NotifyMediaDeviceDetached(const std::string& name);
   void NotifyPowerStateChange();
   void NotifySuspend();
   void NotifyResume();