Webfonts should not block load event for more than one frame

Source/core/fetch/FontResource.h

 /*
  * Copyright (C) 2007, 2008 Apple 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 37 matching lines @@
     FontResource(const ResourceRequest&);
     virtual ~FontResource();
     virtual void trace(Visitor*) OVERRIDE;
 
     virtual void load(ResourceFetcher*, const ResourceLoaderOptions&) OVERRIDE;
 
     virtual void didAddClient(ResourceClient*) OVERRIDE;
 
     virtual void allClientsRemoved() OVERRIDE;
     void beginLoadIfNeeded(ResourceFetcher* dl);
-    virtual bool stillNeedsLoad() const OVERRIDE { return !m_loadInitiated; }
+    virtual bool stillNeedsLoad() const OVERRIDE { return m_state != LoadInitiated; }
     bool exceedsFontLoadWaitLimit() const { return m_exceedsFontLoadWaitLimit; }
 
+    bool loadScheduled() const { return m_state != Unloaded; }
+    void didScheduleLoad();
+    void didUnscheduleLoad();
+
     void setCORSFailed() { m_corsFailed = true; }
     bool isCORSFailed() const { return m_corsFailed; }
 
     bool ensureCustomFontData();
     FontPlatformData platformDataFromCustomData(float size, bool bold, bool italic, FontOrientation = Horizontal, FontWidthVariant = RegularWidth);
 
 #if ENABLE(SVG_FONTS)
     bool ensureSVGFontData();
     SVGFontElement* getSVGFontById(const String&) const;
 #endif
 
 protected:
     virtual bool isSafeToUnlock() const OVERRIDE;
 
 private:
     virtual void checkNotify() OVERRIDE;
     void fontLoadWaitLimitCallback(Timer<FontResource>*);
 
+    enum State { Unloaded, LoadScheduled, LoadInitiated };
+
     OwnPtr<FontCustomPlatformData> m_fontData;
-    bool m_loadInitiated;
+    State m_state;
     bool m_exceedsFontLoadWaitLimit;
     bool m_corsFailed;
     Timer<FontResource> m_fontLoadWaitLimitTimer;
 
 #if ENABLE(SVG_FONTS)
     RefPtrWillBeMember<Document> m_externalSVGDocument;
 #endif
 
     friend class MemoryCache;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(Font);
 
 class FontResourceClient : public ResourceClient {
 public:
     virtual ~FontResourceClient() { }
     static ResourceClientType expectedType() { return FontType; }
     virtual ResourceClientType resourceClientType() const OVERRIDE FINAL { return expectedType(); }
     virtual void fontLoaded(FontResource*) { }
     virtual void didStartFontLoad(FontResource*) { }
     virtual void fontLoadWaitLimitExceeded(FontResource*) { }
 };
 
 }
 
 #endif