Implement CSS font-display

third_party/WebKit/Source/core/css/RemoteFontFaceSource.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef RemoteFontFaceSource_h
 #define RemoteFontFaceSource_h
 
 #include "core/css/CSSFontFaceSource.h"
 #include "core/fetch/FontResource.h"
 #include "core/fetch/ResourcePtr.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
 class FontLoader;
 
+enum FontDisplay {
+    FontDisplayAuto,
+    FontDisplayBlock,
+    FontDisplaySwap,
+    FontDisplayFallback,
+    FontDisplayOptional
+};
+
 class RemoteFontFaceSource final : public CSSFontFaceSource, public FontResourceClient {
 public:
-    explicit RemoteFontFaceSource(FontResource*, PassRefPtrWillBeRawPtr<FontLoader>);
+    explicit RemoteFontFaceSource(FontResource*, PassRefPtrWillBeRawPtr<FontLoader>, FontDisplay);
     ~RemoteFontFaceSource() override;
 
     FontResource* resource() override { return m_font.get(); }
     bool isLoading() const override;
     bool isLoaded() const override;
     bool isValid() const override;
 
     void beginLoadIfNeeded() override;
 
     void didStartFontLoad(FontResource*) override;
     void fontLoaded(FontResource*) override;
-    void fontLoadWaitLimitExceeded(FontResource*) override;
+    void fontLoadShortLimitExceeded(FontResource*) override;
+    void fontLoadLongLimitExceeded(FontResource*) override;
 
     // For UMA reporting
     bool hadBlankText() override { return m_histograms.hadBlankText(); }
     void paintRequested() { m_histograms.fallbackFontPainted(); }
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     PassRefPtr<SimpleFontData> createFontData(const FontDescription&) override;
     PassRefPtr<SimpleFontData> createLoadingFallbackFontData(const FontDescription&);
     void pruneTable();
 
 private:
+    enum DisplayPeriod { BlockPeriod, SwapPeriod, FailurePeriod };
+
     class FontLoadHistograms {
         DISALLOW_ALLOCATION();
     public:
         FontLoadHistograms() : m_loadStartTime(0), m_fallbackPaintTime(0) { }
         void loadStarted();
         void fallbackFontPainted();
         void recordRemoteFont(const FontResource*);
         void recordFallbackTime(const FontResource*);
         bool hadBlankText() { return m_fallbackPaintTime; }
     private:
         const char* histogramName(const FontResource*);
         double m_loadStartTime;
         double m_fallbackPaintTime;
     };
 
+    void switchToSwapPeriod();
+    void switchToFailurePeriod();
+
     ResourcePtr<FontResource> m_font;
     RefPtrWillBeMember<FontLoader> m_fontLoader;
+    const FontDisplay m_display;
+    DisplayPeriod m_period;
     FontLoadHistograms m_histograms;
 };
 
 } // namespace blink
 
 #endif