Allow extension APIs to be called from WebUI.

extensions/browser/event_router.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_BROWSER_EVENT_ROUTER_H_
 #define EXTENSIONS_BROWSER_EVENT_ROUTER_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 304 matching lines @@
   EventRouter::UserGestureState user_gesture;
 
   // Extra information used to filter which events are sent to the listener.
   EventFilteringInfo filter_info;
 
   // If specified, this is called before dispatching an event to each
   // extension. The third argument is a mutable reference to event_args,
   // allowing the caller to provide different arguments depending on the
   // extension and profile. This is guaranteed to be called synchronously with
   // DispatchEvent, so callers don't need to worry about lifetime.
+  //
+  // NOTE: the Extension argument to this may be NULL if this event if it's

[Ken Rockot(use gerrit already), 2014/07/18 22:33:40]

nit: in/on/for* (not if) this event?

[not at google - send to devlin, 2014/07/18 23:28:35]

Done. I had way too many words in here.

+  // possible for this event to be dispatched to non-extension processes, like
+  // WebUI.
   WillDispatchCallback will_dispatch_callback;
 
   // If true, this event will always be dispatched to ephemeral apps, regardless
   // of whether they are running or inactive. Defaults to false.
   // Most events can only be dispatched to ephemeral apps that are already
   // running. Cached ephemeral apps are inactive until launched by the user.
   bool can_load_ephemeral_apps;
 
   Event(const std::string& event_name,
         scoped_ptr<base::ListValue> event_args);
@@ skipping 24 matching lines @@
   // "webRequest.onCompleted/123".
   const std::string event_name;
 
   const std::string extension_id;
   content::BrowserContext* browser_context;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EVENT_ROUTER_H_