Disable SVG Fonts in CSS on all platforms except GDI Windows (XP, Vista)

Source/core/css/CSSFontFaceSrcValue.cpp

 /*
  * Copyright (C) 2007, 2010 Apple 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:
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 16 matching lines @@
 #include "core/css/CSSFontFaceSrcValue.h"
 
 #include "core/FetchInitiatorTypeNames.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/dom/Document.h"
 #include "core/dom/Node.h"
 #include "core/fetch/FetchRequest.h"
 #include "core/fetch/FontResource.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/svg/SVGFontFaceElement.h"
+#include "platform/fonts/FontCache.h"
 #include "platform/fonts/FontCustomPlatformData.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
 
 #if ENABLE(SVG_FONTS)
 bool CSSFontFaceSrcValue::isSVGFontFaceSrc() const
 {
     return equalIgnoringCase(m_format, "svg");
 }
 #endif
 
 bool CSSFontFaceSrcValue::isSupportedFormat() const
 {
     // Normally we would just check the format, but in order to avoid conflicts with the old WinIE style of font-face,
     // we will also check to see if the URL ends with .eot.  If so, we'll go ahead and assume that we shouldn't load it.
     if (m_format.isEmpty()) {
         // Check for .eot.
         if (!m_resource.startsWith("data:", false) && m_resource.endsWith(".eot", false))
             return false;
         return true;
     }
 
-    return FontCustomPlatformData::supportsFormat(m_format)
+    if (FontCustomPlatformData::supportsFormat(m_format))
+        return true;
+
+    // We have removed SVG font support on non-gdi platforms. For details, see:
+    // https://groups.google.com/a/chromium.org/d/msg/blink-dev/pYbbUcYvlYY/LQvFvM8KZZEJ
 #if ENABLE(SVG_FONTS)
-           || isSVGFontFaceSrc()
+    if (RuntimeEnabledFeatures::svgFontsOnNonGDIPlatformsEnabled()
+#if OS(WIN)
+        || !FontCache::useDirectWrite()
 #endif
-           ;
+        )
+        return isSVGFontFaceSrc();
+#endif
+    return false;
 }
 
 String CSSFontFaceSrcValue::customCSSText() const
 {
     StringBuilder result;
     if (isLocal())
         result.appendLiteral("local(");
     else
         result.appendLiteral("url(");
     result.append(m_resource);
@@ skipping 50 matching lines @@
     FetchRequest request(ResourceRequest(resourceURL), FetchInitiatorTypeNames::css);
     document->fetcher()->requestLoadStarted(m_fetched.get(), request, ResourceFetcher::ResourceLoadingFromCache);
 }
 
 bool CSSFontFaceSrcValue::equals(const CSSFontFaceSrcValue& other) const
 {
     return m_isLocal == other.m_isLocal && m_format == other.m_format && m_resource == other.m_resource;
 }
 
 }