[DirectWrite] Force subpixel font sizing to on when DW is enabled

content/renderer/renderer_main_platform_delegate_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/renderer_main_platform_delegate.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/win_util.h"
 #include "base/win/windows_version.h"
 #include "content/common/sandbox_win.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/injection_test_win.h"
 #include "content/public/renderer/render_font_warmup_win.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/renderer/render_thread_impl.h"
 #include "sandbox/win/src/sandbox.h"
 #include "skia/ext/vector_platform_device_emf_win.h"
+#include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
 #include "third_party/WebKit/public/web/win/WebFontRendering.h"
 #include "third_party/icu/source/i18n/unicode/timezone.h"
 #include "third_party/skia/include/ports/SkFontMgr.h"
 #include "third_party/skia/include/ports/SkTypeface_win.h"
 
 #ifdef ENABLE_VTUNE_JIT_INTERFACE
 #include "v8/src/third_party/vtune/v8-vtune.h"
 #endif
 
 #include <dwrite.h>
@@ skipping 64 matching lines @@
 
     if (use_direct_write) {
       WarmupDirectWrite();
     } else {
       SkTypeface_SetEnsureLOGFONTAccessibleProc(SkiaPreCacheFont);
       skia::SetSkiaEnsureTypefaceCharactersAccessible(
           SkiaPreCacheFontCharacters);
     }
   }
   blink::WebFontRendering::setUseDirectWrite(use_direct_write);
-  blink::WebFontRendering::setUseSubpixelPositioning(use_direct_write);
+  if (use_direct_write) {
+    blink::WebRuntimeFeatures::enableSubpixelFontScaling(true);
+  }
 }
 
 void RendererMainPlatformDelegate::PlatformUninitialize() {
 }
 
 bool RendererMainPlatformDelegate::InitSandboxTests(bool no_sandbox) {
   const CommandLine& command_line = parameters_.command_line;
 
   DVLOG(1) << "Started renderer with " << command_line.GetCommandLineString();
 
@@ skipping 41 matching lines @@
     if (run_security_tests) {
       int test_count = 0;
       DVLOG(1) << "Running renderer security tests";
       BOOL result = run_security_tests(&test_count);
       CHECK(result) << "Test number " << test_count << " has failed.";
     }
   }
 }
 
 }  // namespace content