Only deliver extension messages to contexts that care.

chrome/renderer/extensions/extension_helper.cc

Index: chrome/renderer/extensions/extension_helper.cc
diff --git a/chrome/renderer/extensions/extension_helper.cc b/chrome/renderer/extensions/extension_helper.cc
index 3b79e8480597280845fae5a3587702339b2bab04..0441a648d05ea26f87f1f9b7233ddd2394ea44ac 100644
--- a/chrome/renderer/extensions/extension_helper.cc
+++ b/chrome/renderer/extensions/extension_helper.cc
@@ -16,6 +16,7 @@
 #include "chrome/renderer/extensions/event_bindings.h"
 #include "chrome/renderer/extensions/extension_dispatcher.h"
 #include "chrome/renderer/extensions/extension_process_bindings.h"
+#include "chrome/renderer/extensions/renderer_extension_bindings.h"
 #include "chrome/renderer/extensions/user_script_idle_scheduler.h"
 #include "chrome/renderer/extensions/user_script_slave.h"
 #include "content/common/json_value_serializer.h"
@@ -121,6 +122,7 @@ bool ExtensionHelper::OnMessageReceived(const IPC::Message& message) {
   IPC_BEGIN_MESSAGE_MAP(ExtensionHelper, message)
     IPC_MESSAGE_HANDLER(ExtensionMsg_Response, OnExtensionResponse)
     IPC_MESSAGE_HANDLER(ExtensionMsg_MessageInvoke, OnExtensionMessageInvoke)
+    IPC_MESSAGE_HANDLER(ExtensionMsg_DeliverMessage, OnExtensionDeliverMessage)
     IPC_MESSAGE_HANDLER(ExtensionMsg_ExecuteCode, OnExecuteCode)
     IPC_MESSAGE_HANDLER(ExtensionMsg_GetApplicationInfo, OnGetApplicationInfo)
     IPC_MESSAGE_HANDLER(ExtensionMsg_UpdateBrowserWindowId,
@@ -204,6 +206,11 @@ void ExtensionHelper::OnExtensionMessageInvoke(const std::string& extension_id,
       extension_id, function_name, args, render_view(), event_url);
 }
 
+void ExtensionHelper::OnExtensionDeliverMessage(int target_id,
+                                                const std::string& message) {
+  RendererExtensionBindings::DeliverMessage(target_id, message, render_view());
+}
+
 void ExtensionHelper::OnExecuteCode(
     const ExtensionMsg_ExecuteCode_Params& params) {
   WebView* webview = render_view()->webview();