Make printing work better with OOPIF. (try 2)

content/public/renderer/render_frame_observer.h

Index: content/public/renderer/render_frame_observer.h
diff --git a/content/public/renderer/render_frame_observer.h b/content/public/renderer/render_frame_observer.h
index 26a01b1af85d09c0e77ce6df79457567d7c3cba8..4734a068f49ad2011d07ee6ad9b94697eb06f3c4 100644
--- a/content/public/renderer/render_frame_observer.h
+++ b/content/public/renderer/render_frame_observer.h
@@ -121,6 +121,9 @@ class CONTENT_EXPORT RenderFrameObserver : public IPC::Listener,
   // Called when accessibility is enabled or disabled.
   virtual void AccessibilityModeChanged() {}
 
+  // Called when script in the page calls window.print().
+  virtual void ScriptedPrint(bool user_initiated) {}
+
   // IPC::Listener implementation.
   bool OnMessageReceived(const IPC::Message& message) override;