Introduce EphemeralRange::nodes() helper to traverse over a range.

third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp

 /*
  * Copyright (C) 2005 Apple Computer, 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 419 matching lines @@
     updatePositionForTextRemoval(node, offset, count, m_endingPosition);
     updatePositionForTextRemoval(node, offset, count, m_leadingWhitespace);
     updatePositionForTextRemoval(node, offset, count, m_trailingWhitespace);
     updatePositionForTextRemoval(node, offset, count, m_downstreamEnd);
 
     CompositeEditCommand::deleteTextFromNode(node, offset, count);
 }
 
 void DeleteSelectionCommand::makeStylingElementsDirectChildrenOfEditableRootToPreventStyleLoss(EditingState* editingState)
 {
-    Range* range = createRange(m_selectionToDelete.toNormalizedEphemeralRange());
-    Node* node = range->firstNode();
-    while (node && node != range->pastLastNode()) {
-        Node* nextNode = NodeTraversal::next(*node);
-        if (isHTMLStyleElement(*node) || isHTMLLinkElement(*node)) {
-            nextNode = NodeTraversal::nextSkippingChildren(*node);
-            Element* element = rootEditableElement(*node);
+    auto iterableRange = m_selectionToDelete.toNormalizedEphemeralRange().nodes();
+    for (auto it = iterableRange.begin(), end = iterableRange.end(); !it.isNull() && it != end;) {

[yosin_UTC9, 2016/08/18 02:11:09]

We could write this loop as (copied from another message):
by using node generator loop and node processing loop

Vector<Node> linkOrStyleElements;
for (Node& node : m_slectionToDelete.toNormalizedEphemeralRange().nodes()) {
  if (!isHTMLStyleElement(node) && !isHTMLLinkELement(node))
    continue;
  linkOrStyleElements.append(ndoe);
}

for (Node& node : linkOrStyleEements) {
  Element* rootEditable = rootEditableElement(node);
  if (!rootEditable)
    continue;
  removeNode(&node, editingState);
  appendNode(&node, element, editingState);
}

+        Node& node = *it;
+        if (isHTMLStyleElement(node) || isHTMLLinkElement(node)) {
+            Node* nextNode = NodeTraversal::nextSkippingChildren(node);
+            Element* element = rootEditableElement(node);
             if (element) {
-                removeNode(node, editingState);
+                removeNode(&node, editingState);
                 if (editingState->isAborted())
                     return;
-                appendNode(node, element, editingState);
+                appendNode(&node, element, editingState);
                 if (editingState->isAborted())
                     return;
             }
+            it.setCurrent(nextNode);
+        } else {
+            ++it;
         }
-        node = nextNode;
     }
 }
 
 void DeleteSelectionCommand::handleGeneralDelete(EditingState* editingState)
 {
     if (m_upstreamStart.isNull())
         return;
 
     int startOffset = m_upstreamStart.computeEditingOffset();
     Node* startNode = m_upstreamStart.anchorNode();
@@ skipping 496 matching lines @@
     visitor->trace(m_deleteIntoBlockquoteStyle);
     visitor->trace(m_startRoot);
     visitor->trace(m_endRoot);
     visitor->trace(m_startTableRow);
     visitor->trace(m_endTableRow);
     visitor->trace(m_temporaryPlaceholder);
     CompositeEditCommand::trace(visitor);
 }
 
 } // namespace blink