Fix nullptr dereference in MojoBindingsController

content/renderer/mojo_bindings_controller.cc

Index: content/renderer/mojo_bindings_controller.cc
diff --git a/content/renderer/mojo_bindings_controller.cc b/content/renderer/mojo_bindings_controller.cc
index 56cf602c0c39c83ba24d9d2a6dfcd23af4d509dc..99fdf2aa69b948ae444f421693873a547980fb7f 100644
--- a/content/renderer/mojo_bindings_controller.cc
+++ b/content/renderer/mojo_bindings_controller.cc
@@ -38,6 +38,8 @@ MojoBindingsController::~MojoBindingsController() {
 void MojoBindingsController::CreateContextState() {
   v8::HandleScope handle_scope(blink::mainThreadIsolate());
   blink::WebLocalFrame* frame = render_frame()->GetWebFrame();
+  if (!frame)
+    return;
   v8::Local<v8::Context> context = frame->mainWorldScriptContext();
   gin::PerContextData* context_data = gin::PerContextData::From(context);
   MojoContextStateData* data = new MojoContextStateData;