Allow creating font data while FontResource is revalidating

third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/RemoteFontFaceSource.h"
 
 #include "core/css/CSSCustomFontData.h"
 #include "core/css/CSSFontFace.h"
 #include "core/css/CSSFontSelector.h"
 #include "core/dom/Document.h"
@@ skipping 188 matching lines @@
 
   return networkIsSlow && m_display == FontDisplayAuto;
 }
 
 bool RemoteFontFaceSource::isLowPriorityLoadingAllowedForRemoteFont() const {
   return m_isInterventionTriggered;
 }
 
 PassRefPtr<SimpleFontData> RemoteFontFaceSource::createFontData(
     const FontDescription& fontDescription) {
-  if (!isLoaded())
+  if (!isLoaded() && !m_font->hasCustomFontData())

[Takashi Toyoshima, 2017/02/23 03:21:37]

Should we still have the check of !isLoaded() here?
I think hascustomFontData() returning true exactly means that the notifyFinished
was already called, right?

     return createLoadingFallbackFontData(fontDescription);
 
   if (!m_font->ensureCustomFontData() || m_period == FailurePeriod)

[Takashi Toyoshima, 2017/02/23 03:21:37]

I'm not sure these checks are still reasonable.

Could you merge checks 209 through 213 just like

if (!m_font->ensureCustomFontData())
  return createLoadingFallbackFontData(fontDescription);

Also, how returning nullptr makes difference from returning fallback font data?

     return nullptr;
 
   m_histograms.recordFallbackTime(m_font.get());
 
   return SimpleFontData::create(
       m_font->platformDataFromCustomData(fontDescription.effectiveFontSize(),
                                          fontDescription.isSyntheticBold(),
                                          fontDescription.isSyntheticItalic(),
                                          fontDescription.orientation(),
                                          fontDescription.variationSettings()),
@@ skipping 243 matching lines @@
       return Miss;
     case FromUnknown:
     // Fall through.
     default:
       NOTREACHED();
   }
   return Miss;
 }
 
 }  // namespace blink