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

chrome/renderer/extensions/miscellaneous_bindings.h

Index: chrome/renderer/extensions/miscellaneous_bindings.h
diff --git a/chrome/renderer/extensions/miscellaneous_bindings.h b/chrome/renderer/extensions/miscellaneous_bindings.h
index 8fb563e44a037b2c22d9d354a1ddc506fa350898..bdd50f3da80189b64516a2c5e39622969ee453ee 100644
--- a/chrome/renderer/extensions/miscellaneous_bindings.h
+++ b/chrome/renderer/extensions/miscellaneous_bindings.h
@@ -11,6 +11,7 @@
 
 namespace base {
 class DictionaryValue;
+class ListValue;
 }
 
 namespace content {
@@ -55,7 +56,7 @@ class MiscellaneousBindings {
   static void DeliverMessage(
       const ChromeV8ContextSet::ContextSet& context_set,
       int target_port_id,
-      const std::string& message,
+      const base::ListValue& message,
       content::RenderView* restrict_to_render_view);
 
   // Dispatches the Port.onDisconnect event in response to the channel being