[cleanup][v8] Replace uses of deprecated API

Bug: v8:7294 v8:8015
Change-Id: I698f6fd6312dad6d27924d8c000375f4bcd0455f
Reviewed-on: https://chromium-review.googlesource.com/1238538Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594635}

extensions/renderer/object_backed_native_handler.cc

@@ -51,7 +51,8 @@ v8::Local<v8::Object> ObjectBackedNativeHandler::NewInstance() {
   DCHECK_EQ(kInitialized, init_state_)
       << "Initialize() must be called before a new instance is created!";
   return v8::Local<v8::ObjectTemplate>::New(GetIsolate(), object_template_)
-      ->NewInstance();
+      ->NewInstance(GetIsolate()->GetCurrentContext())
+      .ToLocalChecked();
 }
 
 // static