Add support for the "uploadrequired" attribute for Autofill query responses

BUG=84693
TEST=unit_tests --gtest_filter=AutofillDownloadTest.QueryAndUploadTest

Review URL: http://codereview.chromium.org/6969090

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@87729 0039d316-1c4b-4281-b951-d872f2087c98
  void LimitCache(size_t cache_size) {
    download_manager.set_max_form_cache_size(cache_size);
  }

  void LimitCache(size_t cache_size) {
    download_manager.set_max_form_cache_size(cache_size);
  }
