WebFonts cache-aware timeout adaptation

third_party/WebKit/Source/core/fetch/FontResource.h

Index: third_party/WebKit/Source/core/fetch/FontResource.h
diff --git a/third_party/WebKit/Source/core/fetch/FontResource.h b/third_party/WebKit/Source/core/fetch/FontResource.h
index e83ab315a525782642b34205c432c2d1cc84114f..e8543ad0e91052355207852be5e2996083314365 100644
--- a/third_party/WebKit/Source/core/fetch/FontResource.h
+++ b/third_party/WebKit/Source/core/fetch/FontResource.h
@@ -67,6 +67,8 @@ class CORE_EXPORT FontResource final : public Resource {
       bool italic,
       FontOrientation = FontOrientation::Horizontal);
 
+  void willReloadAfterDiskCacheMiss() override;
+
  private:
   class FontResourceFactory : public ResourceFactory {
    public:
@@ -83,12 +85,16 @@ class CORE_EXPORT FontResource final : public Resource {
   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;
@@ -99,6 +105,7 @@ class CORE_EXPORT FontResource final : public Resource {
   Timer<FontResource> m_fontLoadLongLimitTimer;
 
   friend class MemoryCache;
+  friend class FontResourceTestWrapper;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(Font);
@@ -110,6 +117,10 @@ class FontResourceClient : public ResourceClient {
     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. Calls to addClient() and removeClient() in both callbacks
+  // are prohibited to prevent race issues regarding current loading state.
   virtual void fontLoadShortLimitExceeded(FontResource*) {}
   virtual void fontLoadLongLimitExceeded(FontResource*) {}
 };