Turn DocumentParser::pinToMainThread into a cleaner api

Source/core/html/parser/HTMLDocumentParser.h

Index: Source/core/html/parser/HTMLDocumentParser.h
diff --git a/Source/core/html/parser/HTMLDocumentParser.h b/Source/core/html/parser/HTMLDocumentParser.h
index 185ea60687708eaacd528ca5b16e66413116260b..81bf69d2e6a5ff9786ee263ca4caf41773559219 100644
--- a/Source/core/html/parser/HTMLDocumentParser.h
+++ b/Source/core/html/parser/HTMLDocumentParser.h
@@ -40,6 +40,7 @@
 #include "core/html/parser/HTMLToken.h"
 #include "core/html/parser/HTMLTokenizer.h"
 #include "core/html/parser/HTMLTreeBuilderSimulator.h"
+#include "core/html/parser/ParserSynchronizationPolicy.h"
 #include "core/html/parser/TextResourceDecoder.h"
 #include "core/html/parser/XSSAuditor.h"
 #include "core/html/parser/XSSAuditorDelegate.h"
@@ -68,9 +69,9 @@ class HTMLDocumentParser :  public ScriptableDocumentParser, private HTMLScriptR
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(HTMLDocumentParser);
 public:
-    static PassRefPtrWillBeRawPtr<HTMLDocumentParser> create(HTMLDocument& document, bool reportErrors)
+    static PassRefPtrWillBeRawPtr<HTMLDocumentParser> create(HTMLDocument& document, bool reportErrors, ParserSynchronizationPolicy backgroundParsingPolicy)
     {
-        return adoptRefWillBeNoop(new HTMLDocumentParser(document, reportErrors));
+        return adoptRefWillBeNoop(new HTMLDocumentParser(document, reportErrors, backgroundParsingPolicy));
     }
     virtual ~HTMLDocumentParser();
     virtual void trace(Visitor*) override;
@@ -112,7 +113,7 @@ protected:
     virtual void append(PassRefPtr<StringImpl>) override;
     virtual void finish() override final;
 
-    HTMLDocumentParser(HTMLDocument&, bool reportErrors);
+    HTMLDocumentParser(HTMLDocument&, bool reportErrors, ParserSynchronizationPolicy);
     HTMLDocumentParser(DocumentFragment*, Element* contextElement, ParserContentPolicy);
 
     HTMLTreeBuilder* treeBuilder() const { return m_treeBuilder.get(); }
@@ -126,7 +127,6 @@ private:
     }
 
     // DocumentParser
-    virtual void pinToMainThread() override final;
     virtual void detach() override final;
     virtual bool hasInsertionPoint() override final;
     virtual bool processingData() const override final;
@@ -165,7 +165,7 @@ private:
     void attemptToRunDeferredScriptsAndEnd();
     void end();
 
-    bool shouldUseThreading() const { return !m_isPinnedToMainThread; }
+    bool shouldUseThreading() const { return m_shouldUseThreading; }
 
     bool isParsingFragment() const;
     bool isScheduledForResume() const;
@@ -197,7 +197,7 @@ private:
     WeakPtr<BackgroundHTMLParser> m_backgroundParser;
     OwnPtrWillBeMember<HTMLResourcePreloader> m_preloader;
 
-    bool m_isPinnedToMainThread;
+    bool m_shouldUseThreading;
     bool m_endWasDelayed;
     bool m_haveBackgroundParser;
     bool m_tasksWereSuspended;