Report unreadable files as size zero when uploading.

base/file_util.h

 // 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 contains utility functions for dealing with the local
 // filesystem.
 
 #ifndef BASE_FILE_UTIL_H_
 #define BASE_FILE_UTIL_H_
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
+#if defined(UNIT_TEST)
+#include <aclapi.h>
+#endif
 #elif defined(OS_POSIX)
 #include <sys/stat.h>
 #endif
 
 #include <stdio.h>
 
 #include <stack>
 #include <string>
 #include <vector>
 
@@ skipping 470 matching lines @@
 // Renames a file using the SHFileOperation API to ensure that the target file
 // gets the correct default security descriptor in the new path.
 bool RenameFileAndResetSecurityDescriptor(
     const FilePath& source_file_path,
     const FilePath& target_file_path);
 
 // Returns whether the file has been modified since a particular date.
 bool HasFileBeenModifiedSince(const FileEnumerator::FindInfo& find_info,
                               const base::Time& cutoff_time);
 
+#ifdef UNIT_TEST
+
+inline bool MakeFileUnreadable(const FilePath& path) {
+#if defined(OS_POSIX)
+  struct stat stat_buf;
+  if (stat(path.value().c_str(), &stat_buf) != 0)
+    return false;
+  stat_buf.st_mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
+
+  return chmod(path.value().c_str(), stat_buf.st_mode) == 0;
+
+#elif defined(OS_WIN)
+  PACL old_dacl;
+  PSECURITY_DESCRIPTOR security_descriptor;
+  if (GetNamedSecurityInfo(path.value().c_str(), SE_FILE_OBJECT,
+                           DACL_SECURITY_INFORMATION, NULL, NULL, &old_dacl,
+                           NULL, &security_descriptor) != ERROR_SUCCESS)
+    return false;
+
+  // Deny Read access for the current user.
+  EXPLICIT_ACCESS change;
+  change.grfAccessPermissions = GENERIC_READ;
+  change.grfAccessMode = DENY_ACCESS;
+  change.grfInheritance = 0;
+  change.Trustee.pMultipleTrustee = NULL;
+  change.Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
+  change.Trustee.TrusteeForm = TRUSTEE_IS_NAME;
+  change.Trustee.TrusteeType = TRUSTEE_IS_USER;
+  change.Trustee.ptstrName = L"CURRENT_USER";
+
+  PACL new_dacl;
+  if (SetEntriesInAcl(1, &change, old_dacl, &new_dacl) != ERROR_SUCCESS) {
+    LocalFree(security_descriptor);
+    return false;
+  }
+
+  DWORD rc = SetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
+                                  SE_FILE_OBJECT, DACL_SECURITY_INFORMATION,
+                                  NULL, NULL, new_dacl, NULL);
+  LocalFree(security_descriptor);
+  LocalFree(new_dacl);
+
+  return rc == ERROR_SUCCESS;
+#else
+  NOTIMPLEMENTED();
+  return false;
+#endif
+}
+
+#endif  // UNIT_TEST
+
 }  // namespace file_util
 
 // Deprecated functions have been moved to this separate header file,
 // which must be included last after all the above definitions.
 #include "base/file_util_deprecated.h"
 
 #endif  // BASE_FILE_UTIL_H_