Refactor RenderWidgetHost::set_paint_observer()

chrome/browser/automation/automation_provider_observers.cc

Index: chrome/browser/automation/automation_provider_observers.cc
diff --git a/chrome/browser/automation/automation_provider_observers.cc b/chrome/browser/automation/automation_provider_observers.cc
index 505836c3b2636b79451de4e84a3e772a5d4d57a4..ffc267a79e1ef905f3bbda6ec3109ae5eba6f566 100644
--- a/chrome/browser/automation/automation_provider_observers.cc
+++ b/chrome/browser/automation/automation_provider_observers.cc
@@ -1393,7 +1393,8 @@ void PageSnapshotTaker::OnDomOperationCompleted(const std::string& json) {
     // Don't actually start the thumbnail generator, this leads to crashes on
     // Mac, crbug.com/62986. Instead, just hook the generator to the
     // RenderViewHost manually.
-    render_view_->set_painting_observer(generator);
+
+    generator->MonitorRenderer(render_view_, true);
     generator->AskForSnapshot(render_view_, false, callback,
                               entire_page_size_, entire_page_size_);
   }