Update from https://crrev.com/302630

net/disk_cache/simple/simple_index_file.cc

 // Copyright (c) 2013 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.
 
 #include "net/disk_cache/simple/simple_index_file.h"
 
 #include <vector>
 
 #include "base/files/file.h"
 #include "base/files/file_util.h"
@@ skipping 181 matching lines @@
       it->ReadUInt64(&cache_size_);
 }
 
 void SimpleIndexFile::SyncWriteToDisk(net::CacheType cache_type,
                                       const base::FilePath& cache_directory,
                                       const base::FilePath& index_filename,
                                       const base::FilePath& temp_index_filename,
                                       scoped_ptr<Pickle> pickle,
                                       const base::TimeTicks& start_time,
                                       bool app_on_background) {
+  DCHECK_EQ(index_filename.DirName().value(),
+            temp_index_filename.DirName().value());
+  base::FilePath index_file_directory = temp_index_filename.DirName();
+  if (!base::DirectoryExists(index_file_directory) &&
+      !base::CreateDirectory(index_file_directory)) {
+    LOG(ERROR) << "Could not create a directory to hold the index file";
+    return;
+  }
+
   // There is a chance that the index containing all the necessary data about
   // newly created entries will appear to be stale. This can happen if on-disk
   // part of a Create operation does not fit into the time budget for the index
   // flush delay. This simple approach will be reconsidered if it does not allow
   // for maintaining freshness.
   base::Time cache_dir_mtime;
   if (!simple_util::GetMTime(cache_directory, &cache_dir_mtime)) {
     LOG(ERROR) << "Could obtain information about cache age";
     return;
   }
   SerializeFinalData(cache_dir_mtime, pickle.get());
   if (!WritePickleFile(pickle.get(), temp_index_filename)) {
-    if (!base::CreateDirectory(temp_index_filename.DirName())) {
-      LOG(ERROR) << "Could not create a directory to hold the index file";
-      return;
-    }
-    if (!WritePickleFile(pickle.get(), temp_index_filename)) {
-      LOG(ERROR) << "Failed to write the temporary index file";
-      return;
-    }
+    LOG(ERROR) << "Failed to write the temporary index file";
+    return;
   }
 
   // Atomically rename the temporary index file to become the real one.
   // TODO(gavinp): DCHECK when not shutting down, since that is very strange.
   // The rename failing during shutdown is legal because it's legal to begin
   // erasing a cache as soon as the destructor has been called.
   if (!base::ReplaceFile(temp_index_filename, index_filename, NULL))
     return;
 
   if (app_on_background) {
@@ skipping 238 matching lines @@
 bool SimpleIndexFile::LegacyIsIndexFileStale(
     base::Time cache_last_modified,
     const base::FilePath& index_file_path) {
   base::Time index_mtime;
   if (!simple_util::GetMTime(index_file_path, &index_mtime))
     return true;
   return index_mtime < cache_last_modified;
 }
 
 }  // namespace disk_cache