[Extensions] Use a separate IPC message for extension events

extensions/common/event_filtering_info.cc

Index: extensions/common/event_filtering_info.cc
diff --git a/extensions/common/event_filtering_info.cc b/extensions/common/event_filtering_info.cc
index 0f2c7230a2f07618d228104c2d69f1ca1ed0d487..4770d9e95227a951ef3ef9b0de41926115a5b69c 100644
--- a/extensions/common/event_filtering_info.cc
+++ b/extensions/common/event_filtering_info.cc
@@ -7,6 +7,7 @@
 #include <utility>
 
 #include "base/json/json_writer.h"
+#include "base/memory/ptr_util.h"
 #include "base/values.h"
 
 namespace extensions {
@@ -44,11 +45,8 @@ void EventFilteringInfo::SetInstanceID(int instance_id) {
   has_instance_id_ = true;
 }
 
-std::unique_ptr<base::Value> EventFilteringInfo::AsValue() const {
-  if (IsEmpty())
-    return base::Value::CreateNullValue();
-
-  std::unique_ptr<base::DictionaryValue> result(new base::DictionaryValue);
+std::unique_ptr<base::DictionaryValue> EventFilteringInfo::AsValue() const {
+  auto result = base::MakeUnique<base::DictionaryValue>();
   if (has_url_)
     result->SetString("url", url_.spec());
 
@@ -64,12 +62,7 @@ std::unique_ptr<base::Value> EventFilteringInfo::AsValue() const {
   if (has_window_exposed_by_default_)
     result->SetBoolean("windowExposedByDefault", window_exposed_by_default_);
 
-  return std::move(result);
-}
-
-bool EventFilteringInfo::IsEmpty() const {
-  return !has_window_type_ && !has_url_ && service_type_.empty() &&
-         !has_instance_id_ && !has_window_exposed_by_default_;
+  return result;
 }
 
 }  // namespace extensions