[Extensions] Pass EventFilteringInfo directly in DispatchEvent message

extensions/common/event_filtering_info.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef EXTENSIONS_COMMON_EVENT_FILTERING_INFO_H_
 #define EXTENSIONS_COMMON_EVENT_FILTERING_INFO_H_
 
 #include <memory>
+#include <string>
 
 #include "base/optional.h"
 #include "url/gurl.h"
 
-namespace base {
-class DictionaryValue;
-}
-
 namespace extensions {
 
 // Extra information about an event that is used in event filtering.
 //
 // This is the information that is matched against criteria specified in JS
 // extension event listeners. Eg:
 //
 // chrome.someApi.onSomeEvent.addListener(cb,
 //                                        {url: [{hostSuffix: 'google.com'}],
 //                                         tabId: 1});
 struct EventFilteringInfo {
  public:
   EventFilteringInfo();
-  explicit EventFilteringInfo(const base::DictionaryValue& dict);
   EventFilteringInfo(const EventFilteringInfo& other);
   ~EventFilteringInfo();
 
   base::Optional<GURL> url;
   base::Optional<std::string> service_type;
   base::Optional<int> instance_id;
 
   // Note: window type & visible are Chrome concepts, so arguably
   // doesn't belong in the extensions module. If the number of Chrome
   // concept grows, consider a delegation model with a
   // ChromeEventFilteringInfo class.
   base::Optional<std::string> window_type;
 
   // By default events related to windows are filtered based on the
   // listener's extension. This parameter will be set if the listener
   // didn't set any filter on window types.
   base::Optional<bool> window_exposed_by_default;
 
-  std::unique_ptr<base::DictionaryValue> AsValue() const;
+  bool is_empty() const {
+    return !url && !service_type && !instance_id && !window_type &&
+           !window_exposed_by_default;
+  }
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_EVENT_FILTERING_INFO_H_