Clear an extension's filtered events when a context is destroyed.

extensions/renderer/event_bindings.h

 // Copyright 2014 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_RENDERER_EVENT_BINDINGS_H_
 #define EXTENSIONS_RENDERER_EVENT_BINDINGS_H_
 
 #include <set>
 #include <string>
 
@@ skipping 35 matching lines @@
   // the browser we are no longer interested in that event.
   void DetachEvent(const std::string& event_name, bool is_manual);
 
   // MatcherID AttachFilteredEvent(string event_name, object filter)
   // |event_name| Name of the event to attach.
   // |filter| Which instances of the named event are we interested in.
   // returns the id assigned to the listener, which will be returned from calls
   // to MatchAgainstEventFilter where this listener matches.
   void AttachFilteredEvent(const v8::FunctionCallbackInfo<v8::Value>& args);
 
+  // JavaScript handler which forwards to DetachFilteredEvent.
   // void DetachFilteredEvent(int id, bool manual)
-  // id     - Id of the event to detach.
-  // manual - false if this is part of the extension unload process where all
-  //          listeners are automatically detached.
-  void DetachFilteredEvent(const v8::FunctionCallbackInfo<v8::Value>& args);
+  // args[0] forwards to |matcher_id|
+  // args[1] forwards to |is_manual|
+  void DetachFilteredEventHandler(
+      const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  // Detaches a filtered event. Unlike normal events, filtered events are
+  // identified by an ID, not its name.

[Devlin, 2015/07/10 20:44:34]

nitty nit: "not their names" or "a filtered event is"

[not at google - send to devlin, 2015/07/10 20:53:39]

Done.

+  // |matcher_id| The ID of the filtered event.
+  // |is_manual| false if this is part of the extension unload process where all
+  // listeners are automatically detached.
+  void DetachFilteredEvent(int matcher_id, bool is_manual);
 
   void MatchAgainstEventFilter(const v8::FunctionCallbackInfo<v8::Value>& args);
 
   scoped_ptr<EventMatcher> ParseEventMatcher(
-      base::DictionaryValue* filter_dict);
+      scoped_ptr<base::DictionaryValue> filter);
 
   // Called when our context, and therefore us, is invalidated. Run any cleanup.
   void OnInvalidated();
 
-  // The set of attached events. Maintain this so that we can detch them on
-  // unload.
+  // The set of attached events and filtered events. Maintain these so that we
+  // can detch them on unload.
   std::set<std::string> attached_event_names_;
+  std::set<int> attached_matcher_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(EventBindings);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_EVENT_BINDINGS_H_