[Extensions] Use a separate IPC message for extension events

extensions/common/event_filtering_info.h

Index: extensions/common/event_filtering_info.h
diff --git a/extensions/common/event_filtering_info.h b/extensions/common/event_filtering_info.h
index 5578a95c7bcbde4686f1a90009cc7b5cca984014..e6b7f9f7d6b45ed2444cc7d3c59cb6cde825e722 100644
--- a/extensions/common/event_filtering_info.h
+++ b/extensions/common/event_filtering_info.h
@@ -10,7 +10,7 @@
 #include "url/gurl.h"
 
 namespace base {
-class Value;
+class DictionaryValue;
 }
 
 namespace extensions {
@@ -60,8 +60,7 @@ class EventFilteringInfo {
   bool has_service_type() const { return !service_type_.empty(); }
   const std::string& service_type() const { return service_type_; }
 
-  std::unique_ptr<base::Value> AsValue() const;
-  bool IsEmpty() const;
+  std::unique_ptr<base::DictionaryValue> AsValue() const;
 
  private:
   bool has_url_;