Clean up font loading

third_party/WebKit/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 56 matching lines @@
 static void recordPackageFormatHistogram(FontPackageFormat format)
 {
     DEFINE_THREAD_SAFE_STATIC_LOCAL(EnumerationHistogram, packageFormatHistogram, new EnumerationHistogram("WebFont.PackageFormat", PackageFormatEnumMax));
     packageFormatHistogram.count(format);
 }
 
 FontResource* FontResource::fetch(FetchRequest& request, ResourceFetcher* fetcher)
 {
     ASSERT(request.resourceRequest().frameType() == WebURLRequest::FrameTypeNone);
     request.mutableResourceRequest().setRequestContext(WebURLRequest::RequestContextFont);
+    // Defer the load until the font is actually needed unless this is a preload.
+    if (!request.forPreload())
+        request.setDefer(FetchRequest::DeferredByClient);
     return toFontResource(fetcher->requestResource(request, FontResourceFactory()));
 }
 
 FontResource::FontResource(const ResourceRequest& resourceRequest, const ResourceLoaderOptions& options)
     : Resource(resourceRequest, Font, options)
     , m_loadLimitState(UnderLimit)
     , m_corsFailed(false)
     , m_fontLoadShortLimitTimer(this, &FontResource::fontLoadShortLimitCallback)
     , m_fontLoadLongLimitTimer(this, &FontResource::fontLoadLongLimitCallback)
 {
 }
 
 FontResource::~FontResource()
 {
 }
 
-void FontResource::didScheduleLoad()
-{
-    if (getStatus() == NotStarted)
-        setStatus(LoadStartScheduled);
-}
-
-void FontResource::didUnscheduleLoad()
-{
-    if (getStatus() == LoadStartScheduled)
-        setStatus(NotStarted);
-}
-
-void FontResource::load(ResourceFetcher*)
-{
-    // Don't load the file yet. Wait for an access before triggering the load.
-    if (!m_revalidatingRequest.isNull())
-        setStatus(NotStarted);
-}
-
 void FontResource::didAddClient(ResourceClient* c)
 {
     ASSERT(FontResourceClient::isExpectedType(c));
     Resource::didAddClient(c);
     if (isLoaded())
         static_cast<FontResourceClient*>(c)->fontLoaded(this);
     if (m_loadLimitState == ShortLimitExceeded || m_loadLimitState == LongLimitExceeded)
         static_cast<FontResourceClient*>(c)->fontLoadShortLimitExceeded(this);
     if (m_loadLimitState == LongLimitExceeded)
         static_cast<FontResourceClient*>(c)->fontLoadLongLimitExceeded(this);
 }
 
-void FontResource::beginLoadIfNeeded(ResourceFetcher* dl)
+void FontResource::startLoadLimitTimersIfNeeded()
 {
-    if (stillNeedsLoad()) {
-        Resource::load(dl);
-        m_fontLoadShortLimitTimer.startOneShot(fontLoadWaitShortLimitSec, BLINK_FROM_HERE);
-        m_fontLoadLongLimitTimer.startOneShot(fontLoadWaitLongLimitSec, BLINK_FROM_HERE);
-
-        ResourceClientWalker<FontResourceClient> walker(m_clients);
-        while (FontResourceClient* client = walker.next())
-            client->didStartFontLoad(this);
-    }
+    ASSERT(!stillNeedsLoad());
+    if (isLoaded() || m_fontLoadLongLimitTimer.isActive())
+        return;
+    m_fontLoadShortLimitTimer.startOneShot(fontLoadWaitShortLimitSec, BLINK_FROM_HERE);
+    m_fontLoadLongLimitTimer.startOneShot(fontLoadWaitLongLimitSec, BLINK_FROM_HERE);
 }
 
 bool FontResource::ensureCustomFontData()
 {
     if (!m_fontData && !errorOccurred() && !isLoading()) {
         if (m_data)
             m_fontData = FontCustomPlatformData::create(m_data.get(), m_otsParsingMessage);
 
         if (m_fontData) {
             recordPackageFormatHistogram(packageFormatOf(m_data.get()));
@@ skipping 13 matching lines @@
 
 bool FontResource::isSafeToUnlock() const
 {
     return m_data->hasOneRef();
 }
 
 void FontResource::fontLoadShortLimitCallback(Timer<FontResource>*)
 {
     if (!isLoading())
         return;
     ASSERT(m_loadLimitState == UnderLimit);

[Takashi Toyoshima, 2016/04/11 11:51:54]

On reviewing this change, I noticed this assertion fires on Ctrl+R reload, but
not introduced by this change, but exists in trunk.
I'll fix once this change is landed.

     m_loadLimitState = ShortLimitExceeded;
     ResourceClientWalker<FontResourceClient> walker(m_clients);
     while (FontResourceClient* client = walker.next())
         client->fontLoadShortLimitExceeded(this);
 }
 
 void FontResource::fontLoadLongLimitCallback(Timer<FontResource>*)
 {
     if (!isLoading())
         return;
@@ skipping 13 matching lines @@
 void FontResource::checkNotify()
 {
     m_fontLoadShortLimitTimer.stop();
     m_fontLoadLongLimitTimer.stop();
     ResourceClientWalker<FontResourceClient> w(m_clients);
     while (FontResourceClient* c = w.next())
         c->fontLoaded(this);
 }
 
 } // namespace blink