[DirectWrite] Disable subpixel font positioning for old fonts

Source/platform/fonts/win/FontPlatformDataWin.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Computer, Inc.
  * Copyright (c) 2006, 2007, 2008, 2009, 2012 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.
@@ skipping 51 matching lines @@
     if (ts <= kMaxSizeForEmbeddedBitmap)
         flags |= SkPaint::kEmbeddedBitmapText_Flag;
 
     if (ts >= m_minSizeForAntiAlias) {
 
         // Subpixel text positioning looks pretty bad without font smoothing.
         // Disable it unless some type of font smoothing is used. As most tests
         // run without font smoothing we enable it for tests to ensure we get
         // good test coverage matching the more common smoothing enabled
         // behavior.
-        if (m_useSubpixelPositioning
+        if (m_useSubpixelPositioning && ts >= m_minSizeForSubpixel
             && ((textFlags & SkPaint::kAntiAlias_Flag) || LayoutTestSupport::isRunningLayoutTest()))
             flags |= SkPaint::kSubpixelText_Flag;
 
         // Only set painting flags when we're actually painting.
         if (context && !context->couldUseLCDRenderedText()) {
             textFlags &= ~SkPaint::kLCDRenderText_Flag;
             // If we *just* clear our request for LCD, then GDI seems to
             // sometimes give us AA text, and sometimes give us BW text. Since the
             // original intent was LCD, we want to force AA (rather than BW), so we
             // add a special bit to tell Skia to do its best to avoid the BW: by
@@ skipping 69 matching lines @@
 {
     m_paintTextFlags = computePaintTextFlags(fontFamilyName());
 }
 
 bool FontPlatformData::defaultUseSubpixelPositioning()
 {
     return FontCache::fontCache()->useSubpixelPositioning();
 }
 
 } // namespace blink