Add WebContentObserver::OnWebContentsLostFocus()

content/browser/renderer_host/render_view_host_delegate_view.h

Index: content/browser/renderer_host/render_view_host_delegate_view.h
diff --git a/content/browser/renderer_host/render_view_host_delegate_view.h b/content/browser/renderer_host/render_view_host_delegate_view.h
index 03bb3eb8b221e221f72bfc447daf8571759eed87..8eb873c8e854ffe24f137ca6556bb5545d8e01a2 100644
--- a/content/browser/renderer_host/render_view_host_delegate_view.h
+++ b/content/browser/renderer_host/render_view_host_delegate_view.h
@@ -61,6 +61,9 @@ class CONTENT_EXPORT RenderViewHostDelegateView {
   // Notification that view for this delegate got the focus.
   virtual void GotFocus() {}
 
+  // Notification that view for this delegate lost the focus.
+  virtual void LostFocus() {}
+
   // Callback to inform the browser that the page is returning the focus to
   // the browser's chrome. If reverse is true, it means the focus was
   // retrieved by doing a Shift-Tab.