Add a receiver interface to RemovableStorageNotifications.

chrome/browser/system_monitor/media_transfer_protocol_device_observer_linux.cc

Index: chrome/browser/system_monitor/media_transfer_protocol_device_observer_linux.cc
diff --git a/chrome/browser/system_monitor/media_transfer_protocol_device_observer_linux.cc b/chrome/browser/system_monitor/media_transfer_protocol_device_observer_linux.cc
index 8b34e3908f1d634f52e712c558a2d0d57edeaa4b..3e7f062907ef9beb13fcda0e21af4a0e59d172ea 100644
--- a/chrome/browser/system_monitor/media_transfer_protocol_device_observer_linux.cc
+++ b/chrome/browser/system_monitor/media_transfer_protocol_device_observer_linux.cc
@@ -185,16 +185,17 @@ bool MediaTransferProtocolDeviceObserverLinux::GetStorageInfoForPath(
   return true;
 }
 
+void MediaTransferProtocolDeviceObserverLinux::SetNotifications(
+    RemovableStorageNotifications::Receiver* notifications) {
+  notifications_ = notifications;
+}
+
 // device::MediaTransferProtocolManager::Observer override.
 void MediaTransferProtocolDeviceObserverLinux::StorageChanged(
     bool is_attached,
     const std::string& storage_name) {
   DCHECK(!storage_name.empty());
 
-  RemovableStorageNotifications* notifications =
-      RemovableStorageNotifications::GetInstance();
-  DCHECK(notifications);
-
   // New storage is attached.
   if (is_attached) {
     std::string device_id;
@@ -213,14 +214,16 @@ void MediaTransferProtocolDeviceObserverLinux::StorageChanged(
     RemovableStorageNotifications::StorageInfo storage_info(
         device_id, device_name, location);
     storage_map_[location] = storage_info;
-    notifications->ProcessAttach(device_id, device_name, location);
+    if (notifications_)

[vandebo (ex-Chrome), 2013/01/31 23:51:29]

Why the condition?  Should always be true, right?  Passing in the constructor
would ensure that.

[Greg Billock, 2013/02/01 18:28:42]

Yes. This is defensive and mostly done for uniformity -- we do this elsewhere,
for testing reasons. I'll remove if you like, though. Agreed requiring it in the
constructor (everywhere) is the way to go.

[vandebo (ex-Chrome), 2013/02/01 18:59:55]

If everything works without it, then lets go that way so that we don't have to
remember to remove it once the receiver comes in through the constructor.

[Greg Billock, 2013/02/01 23:05:42]

Done.

+      notifications_->ProcessAttach(storage_info);
   } else {
     // Existing storage is detached.
     StorageLocationToInfoMap::iterator it =
         storage_map_.find(GetDeviceLocationFromStorageName(storage_name));
     if (it == storage_map_.end())
       return;
-    notifications->ProcessDetach(it->second.device_id);
+    if (notifications_)
+      notifications_->ProcessDetach(it->second.device_id);
     storage_map_.erase(it);
   }
 }