Webfonts should not block load event for more than one frame

Source/core/fetch/FontResource.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile, Inc.
  *
  * 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
@@ skipping 58 matching lines @@
     return PackageFormatSFNT;
 }
 
 static void recordPackageFormatHistogram(FontPackageFormat format)
 {
     blink::Platform::current()->histogramEnumeration("WebFont.PackageFormat", format, PackageFormatEnumMax);
 }
 
 FontResource::FontResource(const ResourceRequest& resourceRequest)
     : Resource(resourceRequest, Font)
-    , m_loadInitiated(false)
+    , m_state(Unloaded)
     , m_exceedsFontLoadWaitLimit(false)
     , m_corsFailed(false)
     , m_fontLoadWaitLimitTimer(this, &FontResource::fontLoadWaitLimitCallback)
 {
 }
 
 FontResource::~FontResource()
 {
 }
 
 void FontResource::trace(Visitor* visitor)
 {
 #if ENABLE(SVG_FONTS)
     visitor->trace(m_externalSVGDocument);
 #endif
     Resource::trace(visitor);
 }
 
+void FontResource::didScheduleLoad()
+{
+    if (m_state == Unloaded)
+        m_state = LoadScheduled;
+}
+
+void FontResource::didUnscheduleLoad()
+{
+    if (m_state == LoadScheduled)
+        m_state = Unloaded;
+}
+
 void FontResource::load(ResourceFetcher*, const ResourceLoaderOptions& options)
 {
     // Don't load the file yet. Wait for an access before triggering the load.
     setLoading(true);
     m_options = options;
 }
 
 void FontResource::didAddClient(ResourceClient* c)
 {
     ASSERT(c->resourceClientType() == FontResourceClient::expectedType());
     Resource::didAddClient(c);
     if (!isLoading())
         static_cast<FontResourceClient*>(c)->fontLoaded(this);
 }
 
 void FontResource::beginLoadIfNeeded(ResourceFetcher* dl)
 {
-    if (!m_loadInitiated) {
-        m_loadInitiated = true;
+    if (m_state != LoadInitiated) {
+        m_state = LoadInitiated;
         Resource::load(dl, m_options);
         m_fontLoadWaitLimitTimer.startOneShot(fontLoadWaitLimitSec, FROM_HERE);
 
         ResourceClientWalker<FontResourceClient> walker(m_clients);
         while (FontResourceClient* client = walker.next())
             client->didStartFontLoad(this);
     }
 }
 
 bool FontResource::ensureCustomFontData()
@@ skipping 102 matching lines @@
 
 void FontResource::checkNotify()
 {
     m_fontLoadWaitLimitTimer.stop();
     ResourceClientWalker<FontResourceClient> w(m_clients);
     while (FontResourceClient* c = w.next())
         c->fontLoaded(this);
 }
 
 }