Small extensions cleanup: Remove one usage of linked_ptr.

Bug: None
Change-Id: Id27ad0db8e6749efe25aca72d74e023cf9267ac1
Reviewed-on: https://chromium-review.googlesource.com/c/1308083Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Istiaque Ahmed <lazyboy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604746}

extensions/common/api/declarative/declarative_manifest_data.cc

@@ -42,7 +42,7 @@ class ErrorBuilder {
 // type of rule/condition, while the internal format uses a "instanceType" key
 // for this. This function walks through all the conditions and rules to swap
 // the manifest key for the internal key.
-bool ConvertManifestRule(const linked_ptr<DeclarativeManifestData::Rule>& rule,
+bool ConvertManifestRule(const DeclarativeManifestData::Rule& rule,
                          ErrorBuilder* error_builder) {
   auto convert_list =
       [error_builder](const std::vector<std::unique_ptr<base::Value>>& list) {
@@ -63,7 +63,7 @@ bool ConvertManifestRule(const linked_ptr<DeclarativeManifestData::Rule>& rule,
         }
         return true;
       };
-  return convert_list(rule->actions) && convert_list(rule->conditions);
+  return convert_list(rule.actions) && convert_list(rule.conditions);
 }
 
 }  // namespace
@@ -146,7 +146,7 @@ std::unique_ptr<DeclarativeManifestData> DeclarativeManifestData::FromValue(
       return std::unique_ptr<DeclarativeManifestData>();
     }
 
-    if (!ConvertManifestRule(rule, &error_builder))
+    if (!ConvertManifestRule(*rule, &error_builder))
       return std::unique_ptr<DeclarativeManifestData>();
 
     result->event_rules_map_[event].push_back(rule);