Make DOMSelection cache Range

third_party/WebKit/Source/core/editing/SelectionEditor.h

Index: third_party/WebKit/Source/core/editing/SelectionEditor.h
diff --git a/third_party/WebKit/Source/core/editing/SelectionEditor.h b/third_party/WebKit/Source/core/editing/SelectionEditor.h
index cd1e2dafb5194f76847e1f55e337c58bd9b3b2e2..eb4a2019db6f8b41196f83fd80f0fbad3a1de3eb 100644
--- a/third_party/WebKit/Source/core/editing/SelectionEditor.h
+++ b/third_party/WebKit/Source/core/editing/SelectionEditor.h
@@ -82,6 +82,10 @@ class SelectionEditor final
   // layout if needed.
   void updateIfNeeded();
 
+  void cacheRangeOfDocument(Range*);
+  Range* documentCachedRange() const;
+  void clearDocumentCachedRange();
+
   DECLARE_TRACE();
 
  private:
@@ -100,11 +104,15 @@ class SelectionEditor final
   VisibleSelectionInFlatTree m_selectionInFlatTree;
   bool m_observingVisibleSelection;
 
+  // TODO(editing-dev): Removing |m_logicalRange|
   // The range specified by the user, which may not be visually canonicalized
   // (hence "logical"). This will be invalidated if the underlying
   // |VisibleSelection| changes. If that happens, this variable will
   // become |nullptr|, in which case logical positions == visible positions.
   Member<Range> m_logicalRange;
+  // If document is root, document.getSelection().addRange(range) is cached on
+  // this.
+  Member<Range> m_cachedRange;
 };
 
 }  // namespace blink