Remove unused code from DuplicateFinder.

src/parsing/scanner.h

Index: src/parsing/scanner.h
diff --git a/src/parsing/scanner.h b/src/parsing/scanner.h
index 6f6fab554329ef96a9b435b65a2d1efc652812b1..a818ee1d687f793fe944c74c6bc79f3f7cef2d49 100644
--- a/src/parsing/scanner.h
+++ b/src/parsing/scanner.h
@@ -268,7 +268,7 @@ class Scanner {
     return false;
   }
 
-  int FindSymbol(DuplicateFinder* finder, int value);
+  bool FindSymbol(DuplicateFinder* finder);
 
   UnicodeCache* unicode_cache() { return unicode_cache_; }