Return number of values deleted by IDBObjectStore.delete(range)

content/browser/indexed_db/indexed_db_backing_store.cc

Index: content/browser/indexed_db/indexed_db_backing_store.cc
diff --git a/content/browser/indexed_db/indexed_db_backing_store.cc b/content/browser/indexed_db/indexed_db_backing_store.cc
index b33afc020c1bdfe08a258e8271d33bf2ac065ee5..c3fba32e6a96de7a77b90165c648df22d144db4f 100644
--- a/content/browser/indexed_db/indexed_db_backing_store.cc
+++ b/content/browser/indexed_db/indexed_db_backing_store.cc
@@ -1363,14 +1363,19 @@ bool IndexedDBBackingStore::UpdateIDBDatabaseIntVersion(
 static leveldb::Status DeleteRangeBasic(LevelDBTransaction* transaction,
                                         const std::string& begin,
                                         const std::string& end,
-                                        bool upper_open) {
+                                        bool upper_open,
+                                        size_t* delete_count) {
+  DCHECK(delete_count);
   std::unique_ptr<LevelDBIterator> it = transaction->CreateIterator();
   leveldb::Status s;
+  *delete_count = 0;
   for (s = it->Seek(begin); s.ok() && it->IsValid() &&
-                                (upper_open ? CompareKeys(it->Key(), end) < 0
-                                            : CompareKeys(it->Key(), end) <= 0);
-       s = it->Next())
-    transaction->Remove(it->Key());
+                            (upper_open ? CompareKeys(it->Key(), end) < 0
+                                        : CompareKeys(it->Key(), end) <= 0);
+       s = it->Next()) {
+    if (transaction->Remove(it->Key()))
+      (*delete_count)++;
+  }
   return s;
 }
 
@@ -1767,6 +1772,7 @@ leveldb::Status IndexedDBBackingStore::DeleteObjectStore(
   LevelDBTransaction* leveldb_transaction = transaction->transaction();
 
   base::string16 object_store_name;
+  size_t delete_count = 0;
   bool found = false;
   leveldb::Status s =
       GetString(leveldb_transaction,
@@ -1792,8 +1798,8 @@ leveldb::Status IndexedDBBackingStore::DeleteObjectStore(
   s = DeleteRangeBasic(
       leveldb_transaction,
       ObjectStoreMetaDataKey::Encode(database_id, object_store_id, 0),
-      ObjectStoreMetaDataKey::EncodeMaxKey(database_id, object_store_id),
-      true);
+      ObjectStoreMetaDataKey::EncodeMaxKey(database_id, object_store_id), true,
+      &delete_count);
 
   if (s.ok()) {
     leveldb_transaction->Remove(
@@ -1802,16 +1808,16 @@ leveldb::Status IndexedDBBackingStore::DeleteObjectStore(
     s = DeleteRangeBasic(
         leveldb_transaction,
         IndexFreeListKey::Encode(database_id, object_store_id, 0),
-        IndexFreeListKey::EncodeMaxKey(database_id, object_store_id),
-        true);
+        IndexFreeListKey::EncodeMaxKey(database_id, object_store_id), true,
+        &delete_count);
   }
 
   if (s.ok()) {
     s = DeleteRangeBasic(
         leveldb_transaction,
         IndexMetaDataKey::Encode(database_id, object_store_id, 0, 0),
-        IndexMetaDataKey::EncodeMaxKey(database_id, object_store_id),
-        true);
+        IndexMetaDataKey::EncodeMaxKey(database_id, object_store_id), true,
+        &delete_count);
   }
 
   if (!s.ok()) {
@@ -1955,9 +1961,9 @@ leveldb::Status IndexedDBBackingStore::ClearObjectStore(
       KeyPrefix(database_id, object_store_id).Encode();
   const std::string stop_key =
       KeyPrefix(database_id, object_store_id + 1).Encode();
-
-  leveldb::Status s =
-      DeleteRangeBasic(transaction->transaction(), start_key, stop_key, true);
+  size_t delete_count = 0;
+  leveldb::Status s = DeleteRangeBasic(transaction->transaction(), start_key,
+                                       stop_key, true, &delete_count);
   if (!s.ok()) {
     INTERNAL_WRITE_ERROR(CLEAR_OBJECT_STORE);
     return s;
@@ -1993,8 +1999,11 @@ leveldb::Status IndexedDBBackingStore::DeleteRange(
     IndexedDBBackingStore::Transaction* transaction,
     int64_t database_id,
     int64_t object_store_id,
-    const IndexedDBKeyRange& key_range) {
+    const IndexedDBKeyRange& key_range,
+    size_t* exists_delete_count) {
+  DCHECK(exists_delete_count);
   leveldb::Status s;
+  *exists_delete_count = 0;
   std::unique_ptr<IndexedDBBackingStore::Cursor> start_cursor =
       OpenObjectStoreCursor(transaction, database_id, object_store_id,
                             key_range, blink::WebIDBCursorDirectionNext, &s);
@@ -2002,7 +2011,6 @@ leveldb::Status IndexedDBBackingStore::DeleteRange(
     return s;
   if (!start_cursor)
     return leveldb::Status::OK();  // Empty range == delete success.
-
   std::unique_ptr<IndexedDBBackingStore::Cursor> end_cursor =
       OpenObjectStoreCursor(transaction, database_id, object_store_id,
                             key_range, blink::WebIDBCursorDirectionPrev, &s);
@@ -2013,7 +2021,6 @@ leveldb::Status IndexedDBBackingStore::DeleteRange(
     return leveldb::Status::OK();  // Empty range == delete success.
 
   BlobEntryKey start_blob_key, end_blob_key;
-
   std::string start_key = ObjectStoreDataKey::Encode(
       database_id, object_store_id, start_cursor->key());
   base::StringPiece start_key_piece(start_key);
@@ -2033,15 +2040,20 @@ leveldb::Status IndexedDBBackingStore::DeleteRange(
                          false);
   if (!s.ok())
     return s;
-  s = DeleteRangeBasic(transaction->transaction(), start_key, stop_key, false);
+  size_t data_delete_count = 0;
+  s = DeleteRangeBasic(transaction->transaction(), start_key, stop_key, false,
+                       &data_delete_count);
   if (!s.ok())
     return s;
   start_key =
       ExistsEntryKey::Encode(database_id, object_store_id, start_cursor->key());
   stop_key =
       ExistsEntryKey::Encode(database_id, object_store_id, end_cursor->key());
-  return DeleteRangeBasic(
-      transaction->transaction(), start_key, stop_key, false);
+
+  s = DeleteRangeBasic(transaction->transaction(), start_key, stop_key, false,
+                       exists_delete_count);
+  DCHECK_EQ(data_delete_count, *exists_delete_count);
+  return s;
 }
 
 leveldb::Status IndexedDBBackingStore::GetKeyGeneratorCurrentNumber(
@@ -2835,20 +2847,22 @@ leveldb::Status IndexedDBBackingStore::DeleteIndex(
     return InvalidDBKeyStatus();
   LevelDBTransaction* leveldb_transaction = transaction->transaction();
 
+  size_t delete_count = 0;
   const std::string index_meta_data_start =
       IndexMetaDataKey::Encode(database_id, object_store_id, index_id, 0);
   const std::string index_meta_data_end =
       IndexMetaDataKey::EncodeMaxKey(database_id, object_store_id, index_id);
-  leveldb::Status s = DeleteRangeBasic(
-      leveldb_transaction, index_meta_data_start, index_meta_data_end, true);
+  leveldb::Status s =
+      DeleteRangeBasic(leveldb_transaction, index_meta_data_start,
+                       index_meta_data_end, true, &delete_count);
 
   if (s.ok()) {
     const std::string index_data_start =
         IndexDataKey::EncodeMinKey(database_id, object_store_id, index_id);
     const std::string index_data_end =
         IndexDataKey::EncodeMaxKey(database_id, object_store_id, index_id);
-    s = DeleteRangeBasic(
-        leveldb_transaction, index_data_start, index_data_end, true);
+    s = DeleteRangeBasic(leveldb_transaction, index_data_start, index_data_end,
+                         true, &delete_count);
   }
 
   if (!s.ok())