createFragmentFromMarkupWithContext() should use EphemeralRange.

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

Index: third_party/WebKit/Source/core/editing/EphemeralRange.cpp
diff --git a/third_party/WebKit/Source/core/editing/EphemeralRange.cpp b/third_party/WebKit/Source/core/editing/EphemeralRange.cpp
index 641d8b1fabc3f86d48086de4d370729b5ff2d0e4..275f4917904044c5734a2aadbb4785aa0fd96285 100644
--- a/third_party/WebKit/Source/core/editing/EphemeralRange.cpp
+++ b/third_party/WebKit/Source/core/editing/EphemeralRange.cpp
@@ -109,6 +109,20 @@ PositionTemplate<Strategy> EphemeralRangeTemplate<Strategy>::endPosition()
 }
 
 template <typename Strategy>
+Node* EphemeralRangeTemplate<Strategy>::commonAncestorContainer() const
+{
+    return commonAncestorContainer(m_startPosition.computeContainerNode(), m_endPosition.computeContainerNode());
+}
+
+template <typename Strategy>
+Node* EphemeralRangeTemplate<Strategy>::commonAncestorContainer(const Node* containerA, const Node* containerB)
+{
+    if (!containerA || !containerB)
+        return nullptr;
+    return containerA->commonAncestor(*containerB, NodeTraversal::parent);

[Xiaocheng, 2017/02/28 19:26:31]

Should return |Strategy::commonAncestor(*containerA, *containerB)| instead.

EphemeralRangeTemplate<> is a templated class that can be used on either DOM
tree or flat tree, depending on the template parameter |Strategy|.

Strategy::commonAncestor allows us to compute the common ancestor in either of
the trees in a templated manner. On the other hand, NodeTraversal::parent only
allows computing common ancestor in the DOM tree.

[tanvir, 2017/03/02 14:59:14]

Done.

+}
+
+template <typename Strategy>
 bool EphemeralRangeTemplate<Strategy>::isCollapsed() const {
   DCHECK(isValid());
   return m_startPosition == m_endPosition;