Fix lifetime of leveldb::MojoEnv instances.

third_party/leveldatabase/env_chromium.cc

 // Copyright (c) 2011 The LevelDB 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 the AUTHORS file for names of contributors.
 
 #include "third_party/leveldatabase/env_chromium.h"
 
 #include <utility>
 
 #if defined(OS_POSIX)
 #include <dirent.h>
@@ skipping 541 matching lines @@
 
 ChromiumEnv::ChromiumEnv(const std::string& name)
     : kMaxRetryTimeMillis(1000),
       name_(name),
       bgsignal_(&mu_),
       started_bgthread_(false) {
   uma_ioerror_base_name_ = name_ + ".IOError.BFE";
 }
 
 ChromiumEnv::~ChromiumEnv() {
-  // In chromium, ChromiumEnv is leaked. It'd be nice to add NOTREACHED here to
-  // ensure that behavior isn't accidentally changed, but there's an instance in
-  // a unit test that is deleted.
+  // In chromium, ChromiumEnv is leaked. The NOTREACHED here is to ensure that
+  // behavior isn't accidentally changed.
+  NOTREACHED();
 }
 
 bool ChromiumEnv::FileExists(const std::string& fname) {
   return base::PathExists(FilePath::FromUTF8Unsafe(fname));
 }
 
 const char* ChromiumEnv::FileErrorString(base::File::Error error) {
   switch (error) {
     case base::File::FILE_ERROR_FAILED:
       return "No further details.";
@@ skipping 498 matching lines @@
 
 }  // namespace leveldb_env
 
 namespace leveldb {
 
 Env* Env::Default() {
   return leveldb_env::default_env.Pointer();
 }
 
 }  // namespace leveldb