[Code Health] Remove usage of ListValue::GetDictionary() under content

and components

Bug: 1187091
Change-Id: I55c151799e4e682b4a67f0e3c64789d802cd79b7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3259825
Reviewed-by: Danil Somsikov <dsv@chromium.org>
Reviewed-by: Matt Reynolds <mattreynolds@chromium.org>
Reviewed-by: manuk hovanesian <manukh@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Reviewed-by: Elad Alon <eladalon@chromium.org>
Reviewed-by: Ben Kelly <wanderview@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Reviewed-by: Liquan (Max) Gu <maxlg@chromium.org>
Reviewed-by: Xinghui Lu <xinghuilu@chromium.org>
Reviewed-by: Josh Simmons <jds@google.com>
Reviewed-by: Kristi Park <kristipark@chromium.org>
Reviewed-by: Alex Ilin <alexilin@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Reviewed-by: Caitlin Fischer <caitlinfischer@google.com>
Commit-Queue: Nan Lin <linnan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#939907}

components/safe_search_api/safe_search/safe_search_url_checker_client.cc

@@ -56,12 +56,14 @@ bool ParseResponse(const std::string& response, bool* is_porn) {
     DLOG(WARNING) << "ParseResponse expected exactly one result";
     return false;
   }
-  const base::DictionaryValue* classification_dict = nullptr;
-  if (!classifications_list->GetDictionary(0, &classification_dict)) {
+  const base::Value& classification_value = classifications_list->GetList()[0];
+  if (!classification_value.is_dict()) {
     DLOG(WARNING) << "ParseResponse failed to parse classification dict";
     return false;
   }
-  classification_dict->GetBoolean("pornography", is_porn);
+  const base::DictionaryValue& classification_dict =
+      base::Value::AsDictionaryValue(classification_value);
+  classification_dict.GetBoolean("pornography", is_porn);
   return true;
 }