Don't interpret embeded NULLs in a response header line as a line terminator.

BUG=95992

Review URL: http://codereview.chromium.org/7796025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@100863 0039d316-1c4b-4281-b951-d872f2087c98
bool HttpResponseHeaders::GetMimeType(std::string* mime_type) const {
  std::string unused;
  GetMimeTypeAndCharset(mime_type, &unused);
  return !mime_type->empty();
}

bool HttpResponseHeaders::GetMimeType(std::string* mime_type) const {
  std::string unused;
  GetMimeTypeAndCharset(mime_type, &unused);
  return !mime_type->empty();
}
