Add parseFontFaceDescriptor for @font-face handling

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 47 matching lines @@
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
 #include "platform/FontFamilyNames.h"
 #include "platform/SharedBuffer.h"
 
 namespace blink {
 
 static PassRefPtrWillBeRawPtr<CSSValue> parseCSSValue(const Document* document, const String& s, CSSPropertyID propertyID)
 {
     CSSParserContext context(*document, UseCounter::getFrom(document));
-    return CSSParser::parseSingleValue(propertyID, s, context);
+    StringBuilder builder;
+    builder.appendLiteral("@font-face { ");
+    builder.append(getPropertyNameString(propertyID));
+    builder.appendLiteral(" : ");
+    builder.append(s);
+    builder.appendLiteral("; }");
+    RefPtrWillBeRawPtr<StyleRuleBase> rule = CSSParser::parseRule(context, 0, builder.toString());
+    if (!rule || !rule->isFontFaceRule())
+        return nullptr;
+    return toStyleRuleFontFace(rule.get())->properties().getPropertyCSSValue(propertyID);
 }
 
 PassRefPtrWillBeRawPtr<FontFace> FontFace::create(ExecutionContext* context, const AtomicString& family, StringOrArrayBufferOrArrayBufferView& source, const FontFaceDescriptors& descriptors)
 {
     if (source.isString())
         return create(context, family, source.getAsString(), descriptors);
     if (source.isArrayBuffer())
         return create(context, family, source.getAsArrayBuffer(), descriptors);
     if (source.isArrayBufferView())
         return create(context, family, source.getAsArrayBufferView(), descriptors);
@@ skipping 501 matching lines @@
 {
     return m_cssFontFace->hadBlankText();
 }
 
 bool FontFace::hasPendingActivity() const
 {
     return m_status == Loading && executionContext() && !executionContext()->activeDOMObjectsAreStopped();
 }
 
 } // namespace blink