Replace ToLower calls to the new format

chrome/browser/extensions/updater/local_extension_cache_unittest.cc

 // Copyright 2014 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 "chrome/browser/extensions/updater/local_extension_cache.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 87 matching lines @@
                                         const base::Time& timestamp,
                                         base::FilePath* filename) {
     std::string data(size, 0);
 
     crypto::SecureHash* hash =
         crypto::SecureHash::Create(crypto::SecureHash::SHA256);
     hash->Update(data.c_str(), size);
     uint8 output[crypto::kSHA256Length];
     hash->Finish(output, sizeof(output));
     const std::string hex_hash =
-        base::StringToLowerASCII(base::HexEncode(output, sizeof(output)));
+        base::ToLowerASCII(base::HexEncode(output, sizeof(output)));
     delete hash;
 
     const base::FilePath file =
         GetExtensionFileName(dir, id, version, hex_hash);
     if (filename)
       *filename = file;
     EXPECT_EQ(base::WriteFile(file, data.data(), data.size()), int(size));
     EXPECT_TRUE(base::TouchFile(file, timestamp, timestamp));
 
     return hex_hash;
@@ skipping 362 matching lines @@
   const base::FilePath hashed2 =
       GetExtensionFileName(cache_dir, kTestExtensionId1, "3.0", hash4);
   EXPECT_TRUE(base::PathExists(hashed2));
   EXPECT_TRUE(cache.GetExtension(kTestExtensionId1, hash4, NULL, NULL));
   // Old file kept
   EXPECT_TRUE(cache.GetExtension(kTestExtensionId1, hash3, NULL, NULL));
   EXPECT_TRUE(base::DeleteFile(temp7, false));
 }
 
 }  // namespace extensions