Invalidate the previous caret even if the parent text node is removed.

third_party/WebKit/Source/core/editing/FrameSelection.cpp

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 387 matching lines @@
 
 void FrameSelection::nodeWillBeRemoved(Node& node)
 {
     // There can't be a selection inside a fragment, so if a fragment's node is being removed,
     // the selection in the document that created the fragment needs no adjustment.
     if (isNone() || !node.inActiveDocument())
         return;
 
     respondToNodeModification(node, removingNodeRemovesPosition(node, selection().base()), removingNodeRemovesPosition(node, selection().extent()),
         removingNodeRemovesPosition(node, selection().start()), removingNodeRemovesPosition(node, selection().end()));
+
+    if (m_previousCaretNode && node.isSameNode(m_previousCaretNode.get())) {

[yosin_UTC9, 2016/02/24 03:55:25]

|node == m_previousCaretNode|

Node::isSmaeNode() exists for backward compatibility.
https://developer.mozilla.org/en/docs/Web/API/Node/isSameNode

[dshwang, 2016/02/24 13:12:18]

Done.

+        // Hits in ManualTests/caret-paint-after-last-text-is-removed.html
+        DisableCompositingQueryAsserts disabler;
+        invalidateLocalCaretRect(m_previousCaretNode.get(), m_previousCaretRect);
+        m_previousCaretNode = nullptr;
+        m_previousCaretRect = LayoutRect();
+        m_previousCaretVisibility = Hidden;
+    }
 }
 
 static bool intersectsNode(const VisibleSelection& selection, Node* node)
 {
     if (selection.isNone())
         return false;
     Position start = selection.start().parentAnchoredEquivalent();
     Position end = selection.end().parentAnchoredEquivalent();
     TrackExceptionState exceptionState;
     // TODO(yosin) We should avoid to use |Range::intersectsNode()|.
@@ skipping 983 matching lines @@
 
 void showTree(const blink::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
     else
         fprintf(stderr, "Cannot showTree for (nil) FrameSelection.\n");
 }
 
 #endif