[omnibox] SearchSuggestionParser to parse hidden_group_ids from "h".

This CL updates SearchSuggestionParser to look for and parse the "h"
sublist under the "google:headertexts" metadata.

The "h" sublist is used to populate the vector of group IDs that should
be hidden by default.

Only integers are accepted out of the list. All non-integers are
discarded.

Bug: 1106096
Change-Id: Iffad7c7a08f09d18abd027c5c7ccec5b4043da82
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2324890Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Commit-Queue: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792731}

components/omnibox/browser/search_suggestion_parser.cc

@@ -469,7 +469,6 @@ bool SearchSuggestionParser::ParseSuggestResults(
   const base::ListValue* relevances = nullptr;
   const base::ListValue* experiment_stats = nullptr;
   const base::ListValue* suggestion_details = nullptr;
-  const base::DictionaryValue* headers = nullptr;
   const base::ListValue* subtype_identifiers = nullptr;
   const base::DictionaryValue* extras = nullptr;
   const base::Value* suggestsubtypes = nullptr;
@@ -504,9 +503,11 @@ bool SearchSuggestionParser::ParseSuggestResults(
       }
     }
 
-    const base::DictionaryValue* wrapper_dict = nullptr;
-    if (extras->GetDictionary("google:headertexts", &wrapper_dict) &&
-        wrapper_dict && wrapper_dict->GetDictionary("a", &headers) && headers) {
+    const base::DictionaryValue* header_texts = nullptr;
+    if (extras->GetDictionary("google:headertexts", &header_texts) &&
+        header_texts) {
+      const base::DictionaryValue* headers = nullptr;
+      if (header_texts->GetDictionary("a", &headers) && headers) {
         for (const auto& it : headers->DictItems()) {
           int suggestion_group_id;
           base::StringToInt(it.first, &suggestion_group_id);
@@ -515,6 +516,15 @@ bool SearchSuggestionParser::ParseSuggestResults(
         }
       }
 
+      const base::ListValue* hidden_group_ids = nullptr;
+      if (header_texts->GetList("h", &hidden_group_ids) && hidden_group_ids) {
+        for (const auto& value : hidden_group_ids->GetList()) {
+          if (value.is_int())
+            results->hidden_group_ids.emplace_back(value.GetInt());
+        }
+      }
+    }
+
     const base::DictionaryValue* client_data = nullptr;
     if (extras->GetDictionary("google:clientdata", &client_data) && client_data)
       client_data->GetInteger("phi", &prefetch_index);

components/omnibox/browser/search_suggestion_parser.h

@@ -332,8 +332,11 @@ class SearchSuggestionParser {
     // If the relevance values of the results are from the server.
     bool relevances_from_server;
 
-    // The server supplied map of suggestion group Ids to headers.
+    // The server supplied map of suggestion group IDs to header labels.
     HeadersMap headers_map;
+
+    // The server supplied list of group IDs that should be hidden-by-default.
+    std::vector<int> hidden_group_ids;
   };
 
   // Converts JSON loaded by a SimpleURLLoader into UTF-8 and returns the

components/omnibox/browser/search_suggestion_parser_unittest.cc

@@ -251,7 +251,8 @@ TEST(SearchSuggestionParserTest, ParseHeaderInfo) {
           "a":{
             "40007":"Not recommended for you",
             "40008":"Recommended for you"
-          }
+          },
+          "h":[40007, "40008", "garbage_non_int"]
         },
         "google:suggestdetail":[
           {
@@ -280,6 +281,10 @@ TEST(SearchSuggestionParserTest, ParseHeaderInfo) {
       *root_val, input, scheme_classifier, /*default_result_relevance=*/400,
       /*is_keyword_result=*/false, &results));
 
+  // Parse integers, and only integers, out of the "h" metadata list.
+  ASSERT_EQ(1U, results.hidden_group_ids.size());
+  ASSERT_EQ(40007, results.hidden_group_ids[0]);
+
   {
     const auto& suggestion_result = results.suggest_results[0];
     ASSERT_EQ(base::ASCIIToUTF16("los angeles"),