Add WebContentObserver::OnWebContentsLostFocus()

content/browser/renderer_host/render_widget_host_owner_delegate.h

Index: content/browser/renderer_host/render_widget_host_owner_delegate.h
diff --git a/content/browser/renderer_host/render_widget_host_owner_delegate.h b/content/browser/renderer_host/render_widget_host_owner_delegate.h
index 9bc1197fc6ef118644f5d6c68dae5e00afa1d794..3878691b3ed4498ef9b2699606b8b4022d141bc0 100644
--- a/content/browser/renderer_host/render_widget_host_owner_delegate.h
+++ b/content/browser/renderer_host/render_widget_host_owner_delegate.h
@@ -41,6 +41,9 @@ class CONTENT_EXPORT RenderWidgetHostOwnerDelegate {
   // The RenderWidgetHost got the focus.
   virtual void RenderWidgetGotFocus() = 0;
 
+  // The RenderWidgetHost lost the focus.
+  virtual void RenderWidgetLostFocus() = 0;
+
   // The RenderWidgetHost forwarded a mouse event.
   virtual void RenderWidgetDidForwardMouseEvent(
       const blink::WebMouseEvent& mouse_event) = 0;