[DirectWrite] Disable subpixel font positioning for old fonts

Source/platform/fonts/win/FontCacheSkiaWin.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 230 matching lines @@
     };
     size_t numFonts = WTF_ARRAY_LENGTH(minAntiAliasSizeForFont);
     for (size_t i = 0; i < numFonts; i++) {
         FamilyMinSize entry = minAntiAliasSizeForFont[i];
         if (typefacesMatchesFamily(tf.get(), entry.family)) {
             result->setMinSizeForAntiAlias(entry.minSize);
             break;
         }
     }
 
+    // List of fonts that look bad with subpixel text rendering at smaller font
+    // sizes. This includes all fonts in the Microsoft Core fonts for the Web
+    // collection.
+    const static wchar_t* noSubpixelForSmallSizeFont[] = {

[scottmg, 2014/09/05 16:55:41]

nit; sort this list

+        L"arial",
+        L"courier new",
+        L"times new roman",
+        L"andale mono",
+        L"comic sans",
+        L"impact",
+        L"georgia",
+        L"trebuchet",

[scottmg, 2014/09/05 16:55:41]

does this need to be "trebuchet ms"?

+        L"verdana",
+        L"webdings",
+        L"tahoma",
+        L"lucida console"
+    };
+    const static float minSizeForSubpixelForFont = 16.0f;
+    numFonts = WTF_ARRAY_LENGTH(noSubpixelForSmallSizeFont);
+    for (size_t i = 0; i < numFonts; i++) {
+        const wchar_t* family = noSubpixelForSmallSizeFont[i];
+        if (typefacesMatchesFamily(tf.get(), family)) {
+            result->setMinSizeForSubpixel(minSizeForSubpixelForFont);
+            break;
+        }
+    }
+
     return result;
 }
 
 } // namespace blink