Fix some case-insensitive cases for StartsWith

chrome/installer/util/delete_after_reboot_helper.cc

 // Copyright (c) 2010 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.
 //
 // This file defines helper methods used to schedule files for deletion
 // on next reboot. The code here is heavily borrowed and simplified from
 //  http://code.google.com/p/omaha/source/browse/trunk/common/file.cc and
 //  http://code.google.com/p/omaha/source/browse/trunk/common/utils.cc
 //
 // This implementation really is not fast, so do not use it where that will
@@ skipping 308 matching lines @@
   // null-terminated wchar_t strings terminated by an additional null character.
   // Stick this into a vector of strings for clarity.
   HRESULT hr = MultiSZBytesToStringArray(&buffer[0], buffer.size(),
                                          pending_moves);
   return hr;
 }
 
 bool MatchPendingDeletePath(const base::FilePath& short_form_needle,
                             const base::FilePath& reg_path) {
   // Stores the path stored in each entry.
-  std::wstring match_path(reg_path.value());
+  base::string16 match_path(reg_path.value());
 
   // First chomp the prefix since that will mess up GetShortPathName.
-  std::wstring prefix(L"\\??\\");
-  if (base::StartsWith(match_path, prefix, false))
+  base::string16 prefix(L"\\??\\");

[grt (UTC plus 2), 2015/07/01 17:55:42]

nit: base::StringPiece16 prefix(L"\\??\\"); to avoid a memcpy.

+  if (base::StartsWith(match_path, prefix, base::CompareCase::SENSITIVE))
     match_path = match_path.substr(4);

[grt (UTC plus 2), 2015/07/01 17:55:41]

nit: 4 -> prefix.size()

 
   // Get the short path name of the entry.
   base::FilePath short_match_path(GetShortPathName(base::FilePath(match_path)));
 
-  // Now compare the paths. If it isn't one we're looking for, add it
-  // to the list to keep.
-  return base::StartsWith(short_match_path.value(), short_form_needle.value(),
-                          false);
+  // Now compare the paths. It's a match if short_form_needle is a
+  // case-insensitive prefix of short_match_path.
+  if (short_match_path.value().size() < short_form_needle.value().size())
+    return false;
+  DWORD prefix_len = static_cast<DWORD>(short_form_needle.value().size());

[grt (UTC plus 2), 2015/07/01 17:55:42]

base::saturated_cast<DWORD, size_t>()?

+  return ::CompareString(LOCALE_USER_DEFAULT, NORM_IGNORECASE,
+                         short_match_path.value().data(), prefix_len,
+                         short_form_needle.value().data(), prefix_len) ==
+      CSTR_EQUAL;
 }
 
 // Removes all pending moves for the given |directory| and any contained
 // files or subdirectories. Returns true on success
 bool RemoveFromMovesPendingReboot(const base::FilePath& directory) {
   std::vector<PendingMove> pending_moves;
   HRESULT hr = GetPendingMovesValue(&pending_moves);
   if (hr == HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND)) {
     // No pending moves, nothing to do.
     return true;
@@ skipping 37 matching lines @@
         ERROR_SUCCESS);
   }
   std::vector<char> buffer;
   StringArrayToMultiSZBytes(strings_to_keep, &buffer);
   DCHECK_GT(buffer.size(), 0U);
   if (buffer.empty())
     return false;
   return (session_manager_key.WriteValue(kPendingFileRenameOps, &buffer[0],
       buffer.size(), REG_MULTI_SZ) == ERROR_SUCCESS);
 }