Use V8 Maybe APIs in extensions/renderer

extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container.cc

Index: extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container.cc
diff --git a/extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container.cc b/extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container.cc
index fb95d2140c24fa23a79f41a768e34275ab28f7b8..121261add5825fb919ab86e37ee2ca85aa69f85e 100644
--- a/extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container.cc
+++ b/extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container.cc
@@ -43,7 +43,9 @@ class ScriptableObject : public gin::Wrappable<ScriptableObject>,
       base::WeakPtr<MimeHandlerViewContainer> container) {
     ScriptableObject* scriptable_object =
         new ScriptableObject(isolate, container);
-    return gin::CreateHandle(isolate, scriptable_object).ToV8()->ToObject();
+    return gin::CreateHandle(isolate, scriptable_object)
+        .ToV8()
+        .As<v8::Object>();
   }
 
   // gin::NamedPropertyInterceptor
@@ -58,8 +60,13 @@ class ScriptableObject : public gin::Wrappable<ScriptableObject>,
                 isolate, base::Bind(&MimeHandlerViewContainer::PostMessage,
                                     container_, isolate)));
       }
-      return v8::Local<v8::FunctionTemplate>::New(
-                 isolate, post_message_function_template_)->GetFunction();
+      v8::Local<v8::FunctionTemplate> function_template =
+          v8::Local<v8::FunctionTemplate>::New(isolate,
+                                               post_message_function_template_);
+      v8::Local<v8::Function> interceptor;
+      if (function_template->GetFunction(isolate->GetCurrentContext())
+              .ToLocal(&interceptor))
+        return interceptor;
     }
     return v8::Local<v8::Value>();
   }