Added nudge source counters to about:sync.

sync/engine/all_status.h

Index: sync/engine/all_status.h
diff --git a/sync/engine/all_status.h b/sync/engine/all_status.h
index 9649a35fe66a2c82e187cd8462cc495d4b5594d0..6d3e52bb45d11c86593597cbfb0765832a533aac 100644
--- a/sync/engine/all_status.h
+++ b/sync/engine/all_status.h
@@ -17,6 +17,7 @@
 #include "sync/engine/syncer_types.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/engine/sync_status.h"
+#include "sync/engine/nudge_source.h"
 
 namespace syncer {
 
@@ -59,6 +60,8 @@ class AllStatus : public SyncEngineEventListener {
 
   void SetUniqueId(const std::string& guid);
 
+  void IncrementNudgeCounter(NudgeSource source);
+
  protected:
   // Examines syncer to calculate syncing and the unsynced count,
   // and returns a Status with new values.