Webfonts should not block load event for more than one frame

Source/core/fetch/FontResource.cpp

Index: Source/core/fetch/FontResource.cpp
diff --git a/Source/core/fetch/FontResource.cpp b/Source/core/fetch/FontResource.cpp
index 52ab3a1a1157bced05ad972bd5de4a3eb810c12d..1e99662cdbb3e9131f258cefe5b562f10c87ccc1 100644
--- a/Source/core/fetch/FontResource.cpp
+++ b/Source/core/fetch/FontResource.cpp
@@ -76,7 +76,7 @@ static void recordPackageFormatHistogram(FontPackageFormat format)
 
 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)
@@ -95,6 +95,18 @@ void FontResource::trace(Visitor* visitor)
     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.
@@ -112,8 +124,8 @@ void FontResource::didAddClient(ResourceClient* c)
 
 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);