fix: contractions handling in spellchecker (#18506)

This fixes #18459 by improving the handling of contractions in the spellcheck API. Specifically, it now accepts contraction words where the spellchecker recognizes the whole word, and not, as previously, just if it recognizes all of its parts.

atom/renderer/api/atom_api_spell_check_client.h

@@ -6,6 +6,7 @@
 #define ATOM_RENDERER_API_ATOM_API_SPELL_CHECK_CLIENT_H_
 
 #include <memory>
+#include <set>
 #include <string>
 #include <vector>
 
@@ -68,7 +69,7 @@ class SpellCheckClient : public blink::WebSpellCheckPanelHostClient,
   // The javascript function will callback OnSpellCheckDone
   // with the results of all the misspelled words.
   void SpellCheckWords(const SpellCheckScope& scope,
-                       const std::vector<base::string16>& words);
+                       const std::set<base::string16>& words);
 
   // Returns whether or not the given word is a contraction of valid words
   // (e.g. "word:word").