Pass FROM_HERE to ObserverListThreadSafe::Notify to improve profile.

components/storage_monitor/storage_monitor.cc

Index: components/storage_monitor/storage_monitor.cc
diff --git a/components/storage_monitor/storage_monitor.cc b/components/storage_monitor/storage_monitor.cc
index f82995d81a7d57accdfce3963522ab9c344da09d..0f1f6cc6687f0f9b248b443f0676102d6e3b4fdf 100644
--- a/components/storage_monitor/storage_monitor.cc
+++ b/components/storage_monitor/storage_monitor.cc
@@ -172,7 +172,7 @@ void StorageMonitor::ProcessAttach(const StorageInfo& info) {
   DVLOG(1) << "StorageAttached id " << info.device_id();
   if (StorageInfo::IsRemovableDevice(info.device_id())) {
     observer_list_->Notify(
-        &RemovableStorageObserver::OnRemovableStorageAttached, info);
+        FROM_HERE, &RemovableStorageObserver::OnRemovableStorageAttached, info);
   }
 }
 
@@ -190,7 +190,7 @@ void StorageMonitor::ProcessDetach(const std::string& id) {
   DVLOG(1) << "StorageDetached for id " << id;
   if (StorageInfo::IsRemovableDevice(info.device_id())) {
     observer_list_->Notify(
-        &RemovableStorageObserver::OnRemovableStorageDetached, info);
+        FROM_HERE, &RemovableStorageObserver::OnRemovableStorageDetached, info);
   }
 }