Add Media device notification to SystemMonitor and Mac impl

base/system_monitor/system_monitor_mac.mm

Index: base/system_monitor/system_monitor_mac.mm
diff --git a/base/system_monitor/system_monitor_mac.mm b/base/system_monitor/system_monitor_mac.mm
index baaadf052db913eb7f3c548f81c545901f6192e8..f9a92cc911208b11cceff20040633e92636d7e60 100644
--- a/base/system_monitor/system_monitor_mac.mm
+++ b/base/system_monitor/system_monitor_mac.mm
@@ -7,9 +7,14 @@
 
 #include "base/system_monitor/system_monitor.h"
 
+#include <Carbon/Carbon.h>
+#include <CoreFoundation/CoreFoundation.h>
 #include <IOKit/pwr_mgt/IOPMLib.h>
 #include <IOKit/IOMessage.h>
 
+#include "base/mac/foundation_util.h"
+#include "base/sys_string_conversions.h"
+
 namespace base {
 
 namespace {
@@ -37,6 +42,73 @@ void SystemPowerEventCallback(void*,
   }
 }
 
+bool GetDeviceInfo(unsigned long device_number, std::string* name,
+                   FilePath* location) {
+  ICACopyObjectPropertyDictionaryPB properties_request;
+  properties_request.object = device_number;
+  CFDictionaryRef device_properties;
+  properties_request.theDict = &device_properties;
+  OSErr ret = ICACopyObjectPropertyDictionary(&properties_request, NULL);
+  CHECK_EQ(ret, noErr);
+
+  // For now, we only support mass storage media devices.
+  CFStringRef volume = mac::GetValueFromDictionary<CFStringRef>(
+      device_properties, CFSTR("volume"));
+  if (volume == NULL) {
+    CFRelease(device_properties);
+    return false;
+  }
+  *location = FilePath("/Volumes/").Append(SysCFStringRefToUTF8(volume));
+
+  CFStringRef device_name = mac::GetValueFromDictionary<CFStringRef>(
+      device_properties, CFSTR("ICAUserAssignedDeviceNameKey"));
+  if (device_name == NULL) {
+    device_name = mac::GetValueFromDictionary<CFStringRef>(
+        device_properties, CFSTR("ifil"));
+  }
+  if (device_name == NULL) {
+    CFRelease(device_properties);
+    return false;
+  }
+  *name = SysCFStringRefToUTF8(device_name);
+
+  CFRelease(device_properties);
+  return true;
+}
+
+void MediaDeviceNotificationCallback(CFStringRef notification_type,
+                                     CFDictionaryRef notification_dictionary) {
+  bool attach = false;
+  if (CFStringCompare(notification_type, kICANotificationTypeDeviceAdded, 0) ==
+      kCFCompareEqualTo) {
+    attach = true;
+  } else if (CFStringCompare(notification_type,
+                             kICANotificationTypeDeviceRemoved, 0) !=
+             kCFCompareEqualTo) {
+    return;
+  }
+  CFNumberRef refcon_object = mac::GetValueFromDictionary<CFNumberRef>(
+      notification_dictionary, kICARefconKey);
+  unsigned long refcon;
+  CFNumberGetValue(refcon_object, kCFNumberLongType, &refcon);
+  SystemMonitor* system_monitor = reinterpret_cast<SystemMonitor*>(refcon);
+
+  CFNumberRef device_number_object = mac::GetValueFromDictionary<CFNumberRef>(
+      notification_dictionary, kICANotificationDeviceICAObjectKey);
+  unsigned long device_number;
+  CFNumberGetValue(device_number_object, kCFNumberIntType, &device_number);
+  if (attach) {
+    std::string device_name;
+    FilePath location;
+    if (GetDeviceInfo(device_number, &device_name, &location)) {
+      system_monitor->ProcessMediaDeviceAttached(device_number, device_name,
+                                                 location);
+    }
+  } else {
+    system_monitor->ProcessMediaDeviceDetached(device_number);
+  }
+}
+
 }  // namespace
 
 // The reason we can't include this code in the constructor is because
@@ -69,6 +141,20 @@ void SystemMonitor::PlatformInit() {
       CFRunLoopGetCurrent(),
       IONotificationPortGetRunLoopSource(g_notification_port_ref),
       kCFRunLoopCommonModes);
+
+  ICARegisterForEventNotificationPB notification_request;
+  notification_request.header.refcon = reinterpret_cast<unsigned long>(this);
+  notification_request.objectOfInterest = 0;  // Zero means all objects
+  CFStringRef events_of_interest_array[] = {kICANotificationTypeDeviceAdded,
+                                            kICANotificationTypeDeviceRemoved};
+  CFArrayRef events_of_interest =
+      CFArrayCreate(NULL, (const void**)&events_of_interest_array, 2,
+                    &kCFTypeArrayCallBacks);
+  notification_request.eventsOfInterest = events_of_interest;
+  notification_request.notificationProc = &MediaDeviceNotificationCallback;
+  notification_request.options = NULL;
+  OSErr err = ICARegisterForEventNotification(&notification_request, NULL);
+  CHECK_EQ(err, noErr);
 }
 
 void SystemMonitor::PlatformDestroy() {