Make CSSFontFace::setLoadStatus post a task

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 332 matching lines @@
     default:
       NOTREACHED();
   }
   return emptyString();
 }
 
 void FontFace::setLoadStatus(LoadStatusType status) {
   m_status = status;
   ASSERT(m_status != Error || m_error);
 
   if (m_status == Loaded || m_status == Error) {

[Kunihiko Sakamoto, 2017/01/06 07:05:47]

Having load status in both FontFace and CSSFontFace (with slightly different
meanings) is unfortunate.
Instead, can we make just the promise resolution asynchronous? (i.e. delay the
body of this if-statement using postTask)

[adithyas, 2017/01/06 14:56:13]

SGTM, but this would mean that there would be a delay between the loadStatus
being set and the promise being resolved. Is that okay?

[Kunihiko Sakamoto, 2017/01/10 06:02:12]

Yeah ideally we should change the status inside the posted task, but in various
places we're assuming that m_status is immediately updated when loaded.

This is slightly different from what the spec says, but I don't think this will
cause problems in practice.

     if (m_loadedProperty) {
       if (m_status == Loaded)
         m_loadedProperty->resolve(this);
       else
         m_loadedProperty->reject(m_error.get());
     }
 
     HeapVector<Member<LoadFontCallback>> callbacks;
     m_callbacks.swap(callbacks);
     for (size_t i = 0; i < callbacks.size(); ++i) {
@@ skipping 244 matching lines @@
 }
 
 void FontFace::initCSSFontFace(const unsigned char* data, size_t size) {
   m_cssFontFace = createCSSFontFace(this, m_unicodeRange.get());
   if (m_error)
     return;
 
   RefPtr<SharedBuffer> buffer = SharedBuffer::create(data, size);
   BinaryDataFontFaceSource* source =
       new BinaryDataFontFaceSource(buffer.get(), m_otsParseMessage);
-  if (source->isValid())
-    setLoadStatus(Loaded);
-  else
+  if (source->isValid()) {
+    m_cssFontFace->setLoadStatus(Loading);
+    m_cssFontFace->setLoadStatus(Loaded);
+  } else
     setError(
         DOMException::create(SyntaxError, "Invalid font data in ArrayBuffer."));
   m_cssFontFace->addSource(source);
 }
 
 DEFINE_TRACE(FontFace) {
   visitor->trace(m_style);
   visitor->trace(m_weight);
   visitor->trace(m_stretch);
   visitor->trace(m_unicodeRange);
   visitor->trace(m_variant);
   visitor->trace(m_featureSettings);
   visitor->trace(m_display);
   visitor->trace(m_error);
   visitor->trace(m_loadedProperty);
   visitor->trace(m_cssFontFace);
   visitor->trace(m_callbacks);
   ContextClient::trace(visitor);
 }
 
 bool FontFace::hadBlankText() const {
   return m_cssFontFace->hadBlankText();
 }
 
 bool FontFace::hasPendingActivity() const {
   return m_status == Loading && getExecutionContext();
 }
 
 }  // namespace blink