Only allows extensions to create HTML notifications.

chrome/renderer/chrome_render_view_observer.cc

Index: chrome/renderer/chrome_render_view_observer.cc
diff --git a/chrome/renderer/chrome_render_view_observer.cc b/chrome/renderer/chrome_render_view_observer.cc
index 5093e43c1ee35a2d2e659b99784ac97a63950a07..9d820967d6dfee9bf5bed81c71c2830eb39bd1e2 100644
--- a/chrome/renderer/chrome_render_view_observer.cc
+++ b/chrome/renderer/chrome_render_view_observer.cc
@@ -519,6 +519,12 @@ bool ChromeRenderViewObserver::allowWebComponents(const WebDocument& document,
   return false;
 }
 
+bool ChromeRenderViewObserver::allowHTMLNotifications(
+    const WebDocument& document) {
+  WebSecurityOrigin origin = document.securityOrigin();
+  return HasExtensionPermission(origin, APIPermission::kNotification);
+}
+
 static void SendInsecureContentSignal(int signal) {
   UMA_HISTOGRAM_ENUMERATION("SSL.InsecureContent", signal,
                             INSECURE_CONTENT_NUM_EVENTS);