add device type as an argument in OnDevicesChanged.

base/system_monitor/system_monitor.h

Index: base/system_monitor/system_monitor.h
===================================================================
--- base/system_monitor/system_monitor.h	(revision 148913)
+++ base/system_monitor/system_monitor.h	(working copy)
@@ -51,6 +51,13 @@
     RESUME_EVENT        // The system is being resumed.
   };
 
+  // Type of devices whose change need to be monitored, such as add/remove.
+  enum DeviceType {

[tommi (sloooow) - chröme, 2012/07/30 10:02:28]

MediaDeviceType and DeviceType sound very similar.  Can't we add these values to
the existing MediaDeviceType enumeration?

I realize that MediaDeviceType maps to the MediaDeviceInfo class, but we could
use that as well for audio/video devices.  The only member variable that doesn't
fit is perhaps the 'location' member.

I can see that class growing in the future to support pluggable devices in
general so I'd rather not start forking things now and have two types for
essentially the same thing.

+    DEVTYPE_AUDIO_CAPTURE,  // Audio capture device, e.g., microphone.
+    DEVTYPE_VIDEO_CAPTURE,  // Video capture device, e.g., webcam.
+    DEVTYPE_UNKNOWN,  // Other devices.
+  };
+
   // Type of location data to identify a currently attached media device.
   enum MediaDeviceType {
     TYPE_PATH,  // FilePath::StringType, e.g. a mount point.
@@ -140,7 +147,7 @@
    public:
     // Notification that the devices connected to the system have changed.
     // This is only implemented on Windows currently.
-    virtual void OnDevicesChanged() {}
+    virtual void OnDevicesChanged(DeviceType device_type) {}
 
     // When a media device is attached or detached, one of these two events
     // is triggered.
@@ -178,7 +185,7 @@
   void ProcessPowerMessage(PowerEvent event_id);
 
   // Cross-platform handling of a device change event.
-  void ProcessDevicesChanged();
+  void ProcessDevicesChanged(DeviceType device_type);
   void ProcessMediaDeviceAttached(const std::string& id,
                                   const string16& name,
                                   MediaDeviceType type,
@@ -204,7 +211,7 @@
   void BatteryCheck();
 
   // Functions to trigger notifications.
-  void NotifyDevicesChanged();
+  void NotifyDevicesChanged(DeviceType device_type);
   void NotifyMediaDeviceAttached(const std::string& id,
                                  const string16& name,
                                  MediaDeviceType type,