Add a class to parse answer json.

chrome/browser/autocomplete/search_provider_unittest.cc

Index: chrome/browser/autocomplete/search_provider_unittest.cc
diff --git a/chrome/browser/autocomplete/search_provider_unittest.cc b/chrome/browser/autocomplete/search_provider_unittest.cc
index cdebf964509c0c37106dda7d56872244979141ae..5e6937b0fe216c4f3b7aedcbc86fcc3e13700d66 100644
--- a/chrome/browser/autocomplete/search_provider_unittest.cc
+++ b/chrome/browser/autocomplete/search_provider_unittest.cc
@@ -3418,8 +3418,8 @@ TEST_F(SearchProviderTest, AnswersCache) {
   base::string16 query = base::ASCIIToUTF16("weather los angeles");
   SearchSuggestionParser::SuggestResult suggest_result(
       query, AutocompleteMatchType::SEARCH_HISTORY, query, base::string16(),
-      base::string16(), base::string16(), base::string16(), std::string(),
-      std::string(), false, 1200, false, false, query);
+      base::string16(), base::string16(), base::string16(), nullptr,
+      std::string(), std::string(), false, 1200, false, false, query);
   QueryForInput(ASCIIToUTF16("weather l"), false, false);
   provider_->transformed_default_history_results_.push_back(suggest_result);
   answer = provider_->FindAnswersPrefetchData();