--- a/editor/libeditor/HTMLEditRules.h
+++ b/editor/libeditor/HTMLEditRules.h
@@ -585,17 +585,22 @@ protected:
    * If aListElement has other nodes as its child, they are just removed.
    * Finally, aListElement is removed. and its all children are moved to
    * where the aListElement was.
    *
    * @param aListElement        A <ul>, <ol> or <dl> element.
    */
   MOZ_MUST_USE nsresult RemoveListStructure(Element& aListElement);
 
-  nsresult CacheInlineStyles(nsINode* aNode);
+  /**
+   * CacheInlineStyles() caches style of aNode into mCachedStyles.
+   * This may cause flushing layout at retrieving computed value of CSS
+   * properties.
+   */
+  MOZ_MUST_USE nsresult CacheInlineStyles(nsINode* aNode);
 
   /**
    * ReapplyCachedStyles() restores some styles which are disappeared during
    * handling edit action and it should be restored.  This may cause flushing
    * layout at retrieving computed value of CSS properties.
    */
   MOZ_MUST_USE nsresult ReapplyCachedStyles();