Fixes for leveldb env_chromium unittests while building in GN.

third_party/leveldatabase/env_chromium_unittest.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 "base/file_util.h"
 #include "base/files/file.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/test/test_suite.h"
@@ skipping 190 matching lines @@
   status = leveldb::DB::Open(options, dir.AsUTF8Unsafe(), &db);
   EXPECT_TRUE(status.ok()) << status.ToString();
   std::string value;
   status = db->Get(ReadOptions(), "key", &value);
   EXPECT_TRUE(status.ok()) << status.ToString();
   EXPECT_EQ("value", value);
   delete db;
 
   // Ensure that deleting an ldb file also deletes its backup.
   int orig_ldb_files = CountFilesWithExtension(dir, FPL(".ldb"));
-  int orig_bak_files = CountFilesWithExtension(dir, FPL(".bak"));
   EXPECT_GT(ldb_files, 0);
   EXPECT_EQ(ldb_files, bak_files);
   EXPECT_TRUE(GetFirstLDBFile(dir, &ldb_file));
   options.env->DeleteFile(ldb_file.AsUTF8Unsafe());
   ldb_files = CountFilesWithExtension(dir, FPL(".ldb"));
   bak_files = CountFilesWithExtension(dir, FPL(".bak"));
   EXPECT_EQ(orig_ldb_files - 1, ldb_files);
   EXPECT_EQ(bak_files, ldb_files);
 }
 
 TEST(ChromiumEnv, GetChildrenEmptyDir) {
   base::ScopedTempDir scoped_temp_dir;
   ASSERT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath dir = scoped_temp_dir.path();
 
   Env* env = IDBEnv();
   std::vector<std::string> result;
   leveldb::Status status = env->GetChildren(dir.AsUTF8Unsafe(), &result);
   EXPECT_TRUE(status.ok());
-  EXPECT_EQ(0, result.size());
+  EXPECT_EQ(0U, result.size());
 }
 
 TEST(ChromiumEnv, GetChildrenPriorResults) {
   base::ScopedTempDir scoped_temp_dir;
   ASSERT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath dir = scoped_temp_dir.path();
 
   base::FilePath new_file_dir = dir.Append(FPL("tmp_file"));
   FILE* f = fopen(new_file_dir.AsUTF8Unsafe().c_str(), "w");
   if (f) {
     fputs("Temp file contents", f);
     fclose(f);
   }
 
   Env* env = IDBEnv();
   std::vector<std::string> result;
   leveldb::Status status = env->GetChildren(dir.AsUTF8Unsafe(), &result);
   EXPECT_TRUE(status.ok());
   EXPECT_EQ(1, result.size());
 
   // And a second time should also return one result
   status = env->GetChildren(dir.AsUTF8Unsafe(), &result);
   EXPECT_TRUE(status.ok());
   EXPECT_EQ(1, result.size());
 }
 
 int main(int argc, char** argv) { return base::TestSuite(argc, argv).Run(); }