Update usages of std::map to use ScopedPtrMap.

sync/sessions/nudge_tracker.h

Index: sync/sessions/nudge_tracker.h
diff --git a/sync/sessions/nudge_tracker.h b/sync/sessions/nudge_tracker.h
index ec2277c5052e2d4427bd9d48af8dc5c8874c5b92..7be3b6028f84c59b0b3b0ae3112f389f7505d73b 100644
--- a/sync/sessions/nudge_tracker.h
+++ b/sync/sessions/nudge_tracker.h
@@ -11,6 +11,7 @@
 #include <map>
 
 #include "base/compiler_specific.h"
+#include "base/containers/scoped_ptr_map.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "sync/base/sync_export.h"
@@ -158,10 +159,9 @@ class SYNC_EXPORT_PRIVATE NudgeTracker {
   void SetDefaultNudgeDelay(base::TimeDelta nudge_delay);
 
  private:
-  typedef std::map<ModelType, DataTypeTracker*> TypeTrackerMap;
+  typedef ScopedPtrMap<ModelType, scoped_ptr<DataTypeTracker>> TypeTrackerMap;
 
   TypeTrackerMap type_trackers_;
-  STLValueDeleter<TypeTrackerMap> type_tracker_deleter_;
 
   // Tracks whether or not invalidations are currently enabled.
   bool invalidations_enabled_;