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

chrome/browser/extensions/api/messaging/message_service.h

Index: chrome/browser/extensions/api/messaging/message_service.h
diff --git a/chrome/browser/extensions/api/messaging/message_service.h b/chrome/browser/extensions/api/messaging/message_service.h
index 69c23ef776cbebe7f980445712ca0ec7e691674c..df760f3376f64fc26733cd9d1e8d816c165a8e5a 100644
--- a/chrome/browser/extensions/api/messaging/message_service.h
+++ b/chrome/browser/extensions/api/messaging/message_service.h
@@ -22,6 +22,7 @@ class Profile;
 
 namespace base {
 class DictionaryValue;
+class ListValue;
 }
 
 namespace content {
@@ -82,7 +83,7 @@ class MessageService : public ProfileKeyedAPI,
                                       const std::string& error_message) {}
 
     // Dispatch a message to this end of the communication.
-    virtual void DispatchOnMessage(const std::string& message,
+    virtual void DispatchOnMessage(scoped_ptr<base::ListValue> message,
                                    int target_port_id) = 0;
 
     // MessagPorts that target extensions will need to adjust their keepalive
@@ -144,12 +145,12 @@ class MessageService : public ProfileKeyedAPI,
                             const std::string& error_message) OVERRIDE;
 
   // Sends a message to the given port.
-  void PostMessage(int port_id, const std::string& message);
+  void PostMessage(int port_id, scoped_ptr<base::ListValue> message);
 
   // NativeMessageProcessHost::Client
   virtual void PostMessageFromNativeProcess(
       int port_id,
-      const std::string& message) OVERRIDE;
+      scoped_ptr<base::ListValue> message) OVERRIDE;
 
  private:
   friend class MockMessageService;
@@ -205,10 +206,10 @@ class MessageService : public ProfileKeyedAPI,
       CloseChannel(port_id, error_message);
   }
   void PendingPostMessage(int port_id,
-                          const std::string& message,
+                          scoped_ptr<base::ListValue> message,
                           extensions::ExtensionHost* host) {
     if (host)
-      PostMessage(port_id, message);
+      PostMessage(port_id, message.Pass());
   }
 
   // ProfileKeyedAPI implementation.