Use base::StartWith() in more places when appropriate.

storage/common/fileapi/file_system_util.cc

 // 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.
 
 #include "storage/common/fileapi/file_system_util.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 120 matching lines @@
   for (size_t i = 0; i < num_separators; ++i) {
     std::replace(normalized_path.begin(), normalized_path.end(),
                  base::FilePath::kSeparators[i], kSeparator);
   }
 
   return (IsAbsolute(normalized_path)) ?
       normalized_path : base::FilePath::StringType(kRoot) + normalized_path;
 }
 
 bool VirtualPath::IsAbsolute(const base::FilePath::StringType& path) {
-  return path.find(kRoot) == 0;
+  return base::StartsWith(path, kRoot, base::CompareCase::SENSITIVE);
 }
 
 bool VirtualPath::IsRootPath(const base::FilePath& path) {
   std::vector<base::FilePath::StringType> components;
   VirtualPath::GetComponents(path, &components);
   return (path.empty() || components.empty() ||
           (components.size() == 1 &&
            components[0] == VirtualPath::kRoot));
 }
 
@@ skipping 349 matching lines @@
       return base::File::FILE_ERROR_ABORT;
     case net::ERR_ADDRESS_INVALID:
     case net::ERR_INVALID_URL:
       return base::File::FILE_ERROR_INVALID_URL;
     default:
       return base::File::FILE_ERROR_FAILED;
   }
 }
 
 }  // namespace storage