Fix compile error for gn build of mini_installer

chrome/installer/mini_installer/mini_installer.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.
 
 // mini_installer.exe is the first exe that is run when chrome is being
 // installed or upgraded. It is designed to be extremely small (~5KB with no
 // extra resources linked) and it has two main jobs:
 //   1) unpack the resources (possibly decompressing some)
 //   2) run the real installer (setup.exe) with appropriate flags.
 //
@@ skipping 508 matching lines @@
   ::DeleteFile(archive_path);
   ::DeleteFile(setup_path);
   // Delete the temp dir (if it is empty, otherwise fail).
   ::RemoveDirectory(base_path);
 }
 
 // Returns true if the supplied path supports ACLs.
 bool IsAclSupportedForPath(const wchar_t* path) {
   PathString volume;
   DWORD flags = 0;
-  return ::GetVolumePathName(path, volume.get(), volume.capacity()) &&
-             ::GetVolumeInformation(volume.get(), NULL, 0, NULL, NULL, &flags,
-                                    NULL, 0) && (flags & FILE_PERSISTENT_ACLS);
+  return ::GetVolumePathName(path, volume.get(),
+                             static_cast<DWORD>(volume.capacity())) &&

[grt (UTC plus 2), 2016/02/03 14:54:11]

ah, the size_t -> DWORD conversion was the problem? makes sense.

[gab, 2016/02/03 16:21:45]

Right, sorry forgot to add that to description (and now down 11000 targets to
rebuild before I can repro error because I was playing with my repo..)

+         ::GetVolumeInformation(volume.get(), nullptr, 0, nullptr, nullptr,

[grt (UTC plus 2), 2016/02/03 14:54:11]

we have to stick with C++-03 for a little longer in mini_installer. please
revert to using NULL rather than nullptr.

[gab, 2016/02/03 16:21:45]

Done.

+                                &flags, nullptr, 0) &&
+         (flags & FILE_PERSISTENT_ACLS);
 }
 
 // Retrieves the SID of the default owner for objects created by this user
 // token (accounting for different behavior under UAC elevation, etc.).
 // NOTE: On success the |sid| parameter must be freed with LocalFree().
 bool GetCurrentOwnerSid(wchar_t** sid) {
   HANDLE token;
   if (!::OpenProcessToken(::GetCurrentProcess(), TOKEN_QUERY, &token))
     return false;
 
@@ skipping 356 matching lines @@
 #pragma function(memset)
 void* memset(void* dest, int c, size_t count) {
   void* start = dest;
   while (count--) {
     *reinterpret_cast<char*>(dest) = static_cast<char>(c);
     dest = reinterpret_cast<char*>(dest) + 1;
   }
   return start;
 }
 }  // extern "C"