Don't close background pages if there is a pending response (callback).

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 f516603ea845b7935625739348fbda31661cd7e5..cdff73b3fad78d8b509f878f1cc53783ba91e696 100644
--- a/chrome/renderer/extensions/extension_helper.cc
+++ b/chrome/renderer/extensions/extension_helper.cc
@@ -197,9 +197,14 @@ void ExtensionHelper::OnExtensionResponse(int request_id,
                                           bool success,
                                           const std::string& response,
                                           const std::string& error) {
+  std::string extension_id;
   ExtensionProcessBindings::HandleResponse(
       extension_dispatcher_->v8_context_set(), request_id, success,
-      response, error);
+      response, error, &extension_id);
+
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableLazyBackgroundPages))
+    extension_dispatcher_->CheckIdleStatus(extension_id);
 }
 
 void ExtensionHelper::OnExtensionMessageInvoke(const std::string& extension_id,