Block the HTML parser on external stylesheets

third_party/WebKit/Source/core/html/parser/BackgroundHTMLParser.cpp

 /*
  * Copyright (C) 2013 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 242 matching lines @@
             if (simulatedToken == HTMLTreeBuilderSimulator::ScriptStart) {
                 sendTokensToMainThread();
                 m_startingScript = true;
             }
 
             m_pendingTokens->append(token);
         }
 
         m_token->clear();
 
-        if (simulatedToken == HTMLTreeBuilderSimulator::ScriptEnd || m_pendingTokens->size() >= m_pendingTokenLimit) {
+        if (simulatedToken == HTMLTreeBuilderSimulator::ScriptEnd
+            || simulatedToken == HTMLTreeBuilderSimulator::StyleEnd
+            || simulatedToken == HTMLTreeBuilderSimulator::LinkToken
+            || m_pendingTokens->size() >= m_pendingTokenLimit) {
             sendTokensToMainThread();
             // If we're far ahead of the main thread, yield for a bit to avoid consuming too much memory.
             if (m_input.totalCheckpointTokenCount() > m_outstandingTokenLimit)
                 break;
         }
     }
 }
 
 void BackgroundHTMLParser::sendTokensToMainThread()
 {
@@ skipping 21 matching lines @@
     if (isEmpty) {
         m_loadingTaskRunner->postTask(
             BLINK_FROM_HERE,
             threadSafeBind(&HTMLDocumentParser::notifyPendingParsedChunks, AllowCrossThreadAccess(m_parser)));
     }
 
     m_pendingTokens = adoptPtr(new CompactHTMLTokenStream);
 }
 
 } // namespace blink