Initial work to remove the notion of all extension message payloads as 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>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
+#include "base/values.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "ipc/ipc_sender.h"
 
 class GURL;
 class ExtensionHost;
 class ExtensionDevToolsManager;
 class Profile;
 
 namespace content {
@@ skipping 12 matching lines @@
     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.
   static void DispatchEvent(IPC::Sender* ipc_sender,
                             const std::string& extension_id,
                             const std::string& event_name,
+                            const base::Value& event_args,
+                            const GURL& event_url,
+                            UserGestureState user_gesture);
+  static void DispatchEvent(IPC::Sender* ipc_sender,

[asargent_no_longer_on_chrome, 2012/06/18 16:25:30]

Can you add a comment here saying that this is deprecated and to prefer using
the above version that takes a Value instead of a std::string with JSON?

[Garret Kelly, 2012/06/18 18:15:01]

Done.

+                            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
@@ skipping 33 matching lines @@
       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 std::string& event_args,
       Profile* restrict_to_profile,
       const GURL& event_url);
+  virtual void DispatchEventToExtension(

[asargent_no_longer_on_chrome, 2012/06/18 16:25:30]

add same comment here

[Garret Kelly, 2012/06/18 18:15:01]

Done.

+      const std::string& extension_id,
+      const std::string& event_name,
+      const base::Value& 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,
       Profile* restrict_to_profile,
       const GURL& event_url,
       UserGestureState user_gesture);
@@ skipping 50 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 std::string** event_args);
+      const base::Value** 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_