Remove sync OnTransaction{Start,End} notification

chrome/browser/sync/syncable/transaction_observer.h

Index: chrome/browser/sync/syncable/transaction_observer.h
diff --git a/chrome/browser/sync/syncable/transaction_observer.h b/chrome/browser/sync/syncable/transaction_observer.h
index 5af6a429dac770398733508508328f55450465b5..ebf06cd8e20c6aff6cc29e205da3bad2c85221ca 100644
--- a/chrome/browser/sync/syncable/transaction_observer.h
+++ b/chrome/browser/sync/syncable/transaction_observer.h
@@ -9,23 +9,13 @@
 #include "chrome/browser/sync/syncable/model_type.h"
 #include "chrome/browser/sync/syncable/syncable.h"
 
-namespace tracked_objects {
-class Location;
-}  // namespace tracked_objects
-
 namespace syncable {
 
 class TransactionObserver {
  public:
-  virtual void OnTransactionStart(
-      const tracked_objects::Location& location,
-      const WriterTag& writer) = 0;
   virtual void OnTransactionWrite(
       const ImmutableWriteTransactionInfo& write_transaction_info,
       const ModelTypeBitSet& models_with_changes) = 0;
-  virtual void OnTransactionEnd(
-      const tracked_objects::Location& location,
-      const WriterTag& writer) = 0;
  protected:
   virtual ~TransactionObserver() {}
 };