Refactor extension event distribution to use Values instead of JSON strings.

chrome/browser/extensions/extension_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 CHROME_BROWSER_EXTENSIONS_EXTENSION_EVENT_ROUTER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_EVENT_ROUTER_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 24 matching lines @@
  public:
   // These constants convey the state of our knowledge of whether we're in
   // a user-caused gesture as part of DispatchEvent.
   enum UserGestureState {
     USER_GESTURE_UNKNOWN = 0,
     USER_GESTURE_ENABLED = 1,
     USER_GESTURE_NOT_ENABLED = 2,
   };
 
   // Sends an event via ipc_sender to the given extension. Can be called on
   // any thread.

[bryeung, 2012/07/09 15:12:08]

It would be nice to update the comments here (and below) to document memory
ownership.

[Garret Kelly, 2012/07/09 15:32:29]

Done.

   static void DispatchEvent(IPC::Sender* ipc_sender,
                             const std::string& extension_id,
                             const std::string& event_name,
-                            const base::Value& event_args,
+                            base::ListValue* event_args,
                             const GURL& event_url,
                             UserGestureState user_gesture);
 
-  // This invocation is deprecated. All future consumers of this API should be
-  // sending Values as event arguments, using the above version.
-  static void DispatchEvent(IPC::Sender* ipc_sender,
-                            const std::string& extension_id,
-                            const std::string& event_name,
-                            const std::string& event_args,
-                            const GURL& event_url,
-                            UserGestureState user_gesture);
-
   explicit ExtensionEventRouter(Profile* profile);
   virtual ~ExtensionEventRouter();
 
   // Add or remove the process/extension pair as a listener for |event_name|.
   // Note that multiple extensions can share a process due to process
   // collapsing. Also, a single extension can have 2 processes if it is a split
   // mode extension.
   void AddEventListener(const std::string& event_name,
                         content::RenderProcessHost* process,
                         const std::string& extension_id);
@@ skipping 18 matching lines @@
                                  const std::string& event_name);
 
   // Send an event to every registered extension renderer. If
   // |restrict_to_profile| is non-NULL, then the event will not be sent to other
   // profiles unless the extension has permission (e.g. incognito tab update ->
   // normal profile only works if extension is allowed incognito access). If
   // |event_url| is not empty, the event is only sent to extension with host
   // permissions for this url.
   void DispatchEventToRenderers(
       const std::string& event_name,
-      const std::string& event_args,
+      base::ListValue* event_args,
       Profile* restrict_to_profile,
       const GURL& event_url);
 
   // Same as above, except only send the event to the given extension.
   virtual void DispatchEventToExtension(
       const std::string& extension_id,
       const std::string& event_name,
-      const base::Value& event_args,
+      base::ListValue* event_args,
       Profile* restrict_to_profile,
       const GURL& event_url);
 
-  // This invocation is deprecated. The above variant which uses a Value for
-  // event_args is to be used instead.
-  virtual void DispatchEventToExtension(
-      const std::string& extension_id,
-      const std::string& event_name,
-      const std::string& event_args,
-      Profile* restrict_to_profile,
-      const GURL& event_url);
-
   // Dispatch an event to particular extension. Also include an
   // explicit user gesture indicator.
   virtual void DispatchEventToExtension(
       const std::string& extension_id,
       const std::string& event_name,
-      const std::string& event_args,
+      base::ListValue* event_args,
       Profile* restrict_to_profile,
       const GURL& event_url,
       UserGestureState user_gesture);
 
   // Send different versions of an event to extensions in different profiles.
   // This is used in the case of sending one event to extensions that have
   // incognito access, and another event to extensions that don't (here),
   // in order to avoid sending 2 events to "spanning" extensions.
   // If |cross_incognito_profile| is non-NULL and different from
   // restrict_to_profile, send the event with cross_incognito_args to the
   // extensions in that profile that can't cross incognito.
   void DispatchEventsToRenderersAcrossIncognito(
       const std::string& event_name,
-      const std::string& event_args,
+      base::ListValue* event_args,
       Profile* restrict_to_profile,
-      const std::string& cross_incognito_args,
+      base::ListValue* cross_incognito_args,
       const GURL& event_url);
 
   // Record the Event Ack from the renderer. (One less event in-flight.)
   void OnEventAck(Profile* profile, const std::string& extension_id);
 
  private:
   // The details of an event to be dispatched.
   struct ExtensionEvent;
 
   // The extension and process that contains the event listener for a given
@@ skipping 27 matching lines @@
                                const linked_ptr<ExtensionEvent>& event);
 
   // Returns false when the event is scoped to a profile and the listening
   // extension does not have access to events from that profile. Also fills
   // |event_args| with the proper arguments to send, which may differ if
   // the event crosses the incognito boundary.
   bool CanDispatchEventToProfile(
       Profile* profile,
       const extensions::Extension* extension,
       const linked_ptr<ExtensionEvent>& event,
-      const base::Value** event_args);
+      base::ListValue** event_args);
 
   // Ensures that all lazy background pages that are interested in the given
   // event are loaded, and queues the event if the page is not ready yet.
   // If |extension_id| is non-empty, we load only that extension's page
   // (assuming it is interested in the event).
   void LoadLazyBackgroundPagesForEvent(
       const std::string& extension_id,
       const linked_ptr<ExtensionEvent>& event);
 
   // Possibly loads given extension's background page in preparation to
@@ skipping 22 matching lines @@
 
   // The list of all the lazy (non-persistent) background pages that are
   // listening to events. This is just a cache of the real list, which is
   // stored on disk in the extension prefs.
   ListenerMap lazy_listeners_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionEventRouter);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_EVENT_ROUTER_H_