Should not call FocusController::setFocusedFrame() for detached frame

third_party/WebKit/Source/core/page/FocusController.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nuanti Ltd.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 754 matching lines @@
     }
 
     LocalFrame* newFocusedFrame = (frame && frame->isLocalFrame()) ? toLocalFrame(frame) : nullptr;
     if (newFocusedFrame && newFocusedFrame->view()) {
         Document* document = newFocusedFrame->document();
         Element* focusedElement = document ? document->focusedElement() : nullptr;
         if (focusedElement)
             dispatchFocusEvent(*document, *focusedElement);
     }
 
+    // dispatchBlurEvent/dispatchFocusEvent could have changed the focused frame, or
+    // detached the frame.
+    if (newFocusedFrame && !newFocusedFrame->view())
+        return;
+
     setFocusedFrame(frame, notifyEmbedder);
 }
 
 LocalFrame* FocusController::focusedFrame() const
 {
     // TODO(alexmos): Strengthen this to DCHECK that whoever called this really
     // expected a LocalFrame. Refactor call sites so that the rare cases that
     // need to know about focused RemoteFrames use a separate accessor (to be
     // added).
     if (m_focusedFrame && m_focusedFrame->isRemoteFrame())
@@ skipping 523 matching lines @@
     return consumed;
 }
 
 DEFINE_TRACE(FocusController)
 {
     visitor->trace(m_page);
     visitor->trace(m_focusedFrame);
 }
 
 } // namespace blink