Replace JSON (de)serialization of extension messages with direct Value pickling.

chrome/browser/extensions/message_handler.cc

Index: chrome/browser/extensions/message_handler.cc
diff --git a/chrome/browser/extensions/message_handler.cc b/chrome/browser/extensions/message_handler.cc
index 79b94c9e53bb28a1a100a8a9ccdc55f53731f771..f0576e5f93df4275214d8b73485208f735f3c61d 100644
--- a/chrome/browser/extensions/message_handler.cc
+++ b/chrome/browser/extensions/message_handler.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/extensions/message_handler.h"
 
+#include "base/values.h"
 #include "chrome/browser/extensions/api/messaging/message_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
@@ -43,12 +44,12 @@ void MessageHandler::RenderViewHostInitialized() {
 }
 
 void MessageHandler::OnPostMessage(int port_id,
-                                            const std::string& message) {
+                                   const base::ListValue& message) {
   Profile* profile = Profile::FromBrowserContext(
       render_view_host()->GetProcess()->GetBrowserContext());
   MessageService* message_service = MessageService::Get(profile);
   if (message_service) {
-    message_service->PostMessage(port_id, message);
+    message_service->PostMessage(port_id, make_scoped_ptr(message.DeepCopy()));
   }
 }