Update from https://crrev.com/306655

net/disk_cache/blockfile/block_files.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // See net/disk_cache/disk_cache.h for the public interface.
 
 #ifndef NET_DISK_CACHE_BLOCKFILE_BLOCK_FILES_H_
 #define NET_DISK_CACHE_BLOCKFILE_BLOCK_FILES_H_
 
 #include <vector>
@@ skipping 118 matching lines @@
   // Attemp to grow this file. Fails if the file cannot be extended anymore.
   bool GrowBlockFile(MappedFile* file, BlockFileHeader* header);
 
   // Returns the appropriate file to use for a new block.
   MappedFile* FileForNewBlock(FileType block_type, int block_count);
 
   // Returns the next block file on this chain, creating new files if needed.
   MappedFile* NextFile(MappedFile* file);
 
   // Creates an empty block file and returns its index.
-  int CreateNextBlockFile(FileType block_type);
+  int16 CreateNextBlockFile(FileType block_type);
 
   // Removes a chained block file that is now empty.
   bool RemoveEmptyFile(FileType block_type);
 
   // Restores the header of a potentially inconsistent file.
   bool FixBlockFileHeader(MappedFile* file);
 
   // Retrieves stats for the given file index.
   void GetFileStats(int index, int* used_count, int* load);
 
@@ skipping 10 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(DiskCacheTest, BlockFiles_TruncatedFile);
   FRIEND_TEST_ALL_PREFIXES(DiskCacheTest, BlockFiles_InvalidFile);
   FRIEND_TEST_ALL_PREFIXES(DiskCacheTest, BlockFiles_Stats);
 
   DISALLOW_COPY_AND_ASSIGN(BlockFiles);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_BLOCKFILE_BLOCK_FILES_H_