Revert a workaround commit for a Use-After-Free crash.

Revert a workaround commit r20158 for a Use-After-Free issue (http://crbug.com/244746) because a cleaner CL r207218 is landed.
URLRequestContext does not inherit SupportsWeakPtr now.

R=mmenke
BUG=244746

Review URL: https://chromiumcodereview.appspot.com/16870008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207811 0039d316-1c4b-4281-b951-d872f2087c98
ChromeURLRequestContextGetter::CreateOffTheRecordForExtensions(
    Profile* profile, const ProfileIOData* profile_io_data) {
  DCHECK(profile->IsOffTheRecord());
  return new ChromeURLRequestContextGetter(
      new FactoryForExtensions(profile_io_data));
}

ChromeURLRequestContextGetter::CreateOffTheRecordForExtensions(
    Profile* profile, const ProfileIOData* profile_io_data) {
  DCHECK(profile->IsOffTheRecord());
  return new ChromeURLRequestContextGetter(
      new FactoryForExtensions(profile_io_data));
}
