Simplify state handling in WebVTTTokenizer::nextToken

Source/core/html/track/vtt/VTTTokenizer.h

 /*
  * Copyright (C) 2011 Google Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 58 matching lines @@
         return m_token->type() == WebVTTToken::Type::Character;
     }
 
     inline void bufferCharacter(UChar character)
     {
         ASSERT(character != kEndOfFileMarker);
         m_token->ensureIsCharacterToken();
         m_token->appendToCharacter(character);
     }
 
-    inline bool emitAndResumeIn(SegmentedString& source, State::State state)
+    inline bool advanceAndEmitToken(SegmentedString& source, WebVTTTokenTypes::Type type)
     {
-        m_state = state;
         source.advanceAndUpdateLineNumber();
+        return emitToken(type);
+    }
+
+    inline bool emitToken(WebVTTTokenTypes::Type type)
+    {
+        ASSERT(m_token->type() == type);
         return true;
     }
 
-    inline bool emitEndOfFile(SegmentedString& source)
-    {
-        if (haveBufferedCharacterToken())
-            return true;
-        m_state = State::DataState;
-        source.advanceAndUpdateLineNumber();
-        m_token->clear();
-        m_token->makeEndOfFile();
-        return true;
-    }
-
     bool shouldSkipNullCharacters() const { return true; }
 
 private:
     WebVTTTokenizer();
 
     // m_token is owned by the caller. If nextToken is not on the stack,
     // this member might be pointing to unallocated memory.
     WebVTTToken* m_token;
+
+    // This member does not really need to be an instance member - it's only used in nextToken.
+    // The reason it's stored here is because of the use of the ADVANCE_TO state helpers.
     WebVTTTokenizerState::State m_state;
 
     Vector<LChar, 32> m_buffer;
 
     // ://www.whatwg.org/specs/web-apps/current-work/#preprocessing-the-input-stream
     InputStreamPreprocessor<WebVTTTokenizer> m_inputStreamPreprocessor;
 };
 
 }
 
 #endif