[SyncFS] Introduce counters in LevelDBWrapper

chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h

Index: chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h
diff --git a/chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h b/chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h
index 113e718f9583d413ce35baecbc7e46a2f5bb65cb..7b6c51e11f6c29b74fc62d31f530c2791d28ca2d 100644
--- a/chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h
+++ b/chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h
@@ -89,6 +89,12 @@ class LevelDBWrapper {
   // Clears pending transactions.
   void Clear();
 
+  // Returns the number of pending PUT/DELETE operations.
+  // Each counter counts operations independently, so operations on a key
+  // may be counted more than once.
+  int64 num_puts() { return num_puts_; }
+  int64 num_deletes() { return num_deletes_; }
+
   // TODO(peria): Rename this method to GetLevelDBForTesting, after removing
   // usages of drive_backend::MigrateDatabaseFromVxToVy() under
   // drive_backend_v1/.
@@ -98,6 +104,8 @@ class LevelDBWrapper {
   scoped_ptr<leveldb::DB> db_;
 
   PendingOperationMap pending_;
+  int64 num_puts_;
+  int64 num_deletes_;
 
   DISALLOW_COPY_AND_ASSIGN(LevelDBWrapper);
 };