Updates subpixel positioning and hinting when DSF is changed

ui/gfx/platform_font.h

 // 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.
 
 #ifndef UI_GFX_PLATFORM_FONT_H_
 #define UI_GFX_PLATFORM_FONT_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 46 matching lines @@
   // Returns the specified font name in UTF-8.
   virtual std::string GetFontName() const = 0;
 
   // Returns the actually used font name in UTF-8.
   virtual std::string GetActualFontNameForTesting() const = 0;
 
   // Returns the font size in pixels.
   virtual int GetFontSize() const = 0;
 
   // Returns an object describing how the font should be rendered.
-  virtual const FontRenderParams& GetFontRenderParams() const = 0;
+  virtual const FontRenderParams& GetFontRenderParams() = 0;
 
   // Returns the native font handle.
   virtual NativeFont GetNativeFont() const = 0;
 
  protected:
   virtual ~PlatformFont() {}
 
  private:
   friend class base::RefCounted<PlatformFont>;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_PLATFORM_FONT_H_