WebFonts cache-aware timeout adaptation

third_party/WebKit/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 49 matching lines @@
   bool isCORSFailed() const { return m_corsFailed; }
   String otsParsingMessage() const { return m_otsParsingMessage; }
 
   bool ensureCustomFontData();
   FontPlatformData platformDataFromCustomData(
       float size,
       bool bold,
       bool italic,
       FontOrientation = FontOrientation::Horizontal);
 
+  void willReloadAfterDiskCacheMiss() override;
+
  private:
   class FontResourceFactory : public ResourceFactory {
    public:
     FontResourceFactory() : ResourceFactory(Resource::Font) {}
 
     Resource* create(const ResourceRequest& request,
                      const ResourceLoaderOptions& options,
                      const String& charset) const override {
       return new FontResource(request, options);
     }
   };
   FontResource(const ResourceRequest&, const ResourceLoaderOptions&);
 
   void checkNotify() override;
   void fontLoadShortLimitCallback(TimerBase*);
   void fontLoadLongLimitCallback(TimerBase*);
+  void notifyClientsShortLimitExceeded();
+  void notifyClientsLongLimitExceeded();
 
+  // This is used in UMA histograms, should not change order.
   enum LoadLimitState {
     LoadNotStarted,
     UnderLimit,
     ShortLimitExceeded,
-    LongLimitExceeded
+    LongLimitExceeded,
+    LoadLimitStateEnumMax
   };
 
   std::unique_ptr<FontCustomPlatformData> m_fontData;
   String m_otsParsingMessage;
   LoadLimitState m_loadLimitState;
   bool m_corsFailed;
   Timer<FontResource> m_fontLoadShortLimitTimer;
   Timer<FontResource> m_fontLoadLongLimitTimer;
 
   friend class MemoryCache;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(Font);
 
 class FontResourceClient : public ResourceClient {
  public:
   ~FontResourceClient() override {}
   static bool isExpectedType(ResourceClient* client) {
     return client->getResourceClientType() == FontType;
   }
   ResourceClientType getResourceClientType() const final { return FontType; }
+
+  // If cache-aware loading is activated, both callbacks will be blocked until
+  // disk cache miss. If called on cache miss, calls to addClient() and
+  // removeClient() is prohibited to prevent race issues regarding current
+  // loading state.
   virtual void fontLoadShortLimitExceeded(FontResource*) {}
   virtual void fontLoadLongLimitExceeded(FontResource*) {}
 };
 
 }  // namespace blink
 
 #endif