[Extensions] Check is_valid() in app bindings

chrome/renderer/extensions/app_bindings.cc

Index: chrome/renderer/extensions/app_bindings.cc
diff --git a/chrome/renderer/extensions/app_bindings.cc b/chrome/renderer/extensions/app_bindings.cc
index b64319346513221b56dd112f6757767b7ed9620a..627f4efdaf13239a17322d1119e738eb03b8ed76 100644
--- a/chrome/renderer/extensions/app_bindings.cc
+++ b/chrome/renderer/extensions/app_bindings.cc
@@ -167,6 +167,9 @@ bool AppBindings::OnMessageReceived(const IPC::Message& message) {
 
 void AppBindings::OnAppInstallStateResponse(
     const std::string& state, int callback_id) {
+  if (!is_valid())
+    return;
+
   v8::Isolate* isolate = context()->isolate();
   v8::HandleScope handle_scope(isolate);
   v8::Context::Scope context_scope(context()->v8_context());