Regularize ownerships and lifecycle for storage monitor platform classes.

chrome/browser/storage_monitor/removable_device_notifications_mac.mm

Index: chrome/browser/storage_monitor/removable_device_notifications_mac.mm
diff --git a/chrome/browser/storage_monitor/removable_device_notifications_mac.mm b/chrome/browser/storage_monitor/removable_device_notifications_mac.mm
index bc208869fd88e32665a39eae80fc09d3f2d0bd0b..ef4f76ee611713b196970ddadd147ad2cd341e56 100644
--- a/chrome/browser/storage_monitor/removable_device_notifications_mac.mm
+++ b/chrome/browser/storage_monitor/removable_device_notifications_mac.mm
@@ -70,6 +70,11 @@ RemovableDeviceNotificationsMac::RemovableDeviceNotificationsMac() {
       kDADiskDescriptionWatchVolumePath,
       DiskDescriptionChangedCallback,
       this);
+
+  if (base::mac::IsOSLionOrLater()) {
+    image_capture_device_manager_.reset(new chrome::ImageCaptureDeviceManager);
+    image_capture_device_manager_->SetNotifications(receiver());
+  }
 }
 
 RemovableDeviceNotificationsMac::~RemovableDeviceNotificationsMac() {