Support FontRenderParams on Win; fix RenderTextHarfBuzz.

ui/gfx/font_render_params_linux.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_FONT_RENDER_PARAMS_LINUX_H_
-#define UI_GFX_FONT_RENDER_PARAMS_LINUX_H_
-
-#include "ui/gfx/gfx_export.h"
-
-namespace gfx {
-
-// A collection of parameters describing how text should be rendered on Linux.
-struct GFX_EXPORT FontRenderParams {
-  // No constructor to avoid static initialization.
-
-  // Level of hinting to be applied.
-  enum Hinting {
-    HINTING_NONE = 0,
-    HINTING_SLIGHT,
-    HINTING_MEDIUM,
-    HINTING_FULL,
-  };
-
-  // Different subpixel orders to be used for subpixel rendering.
-  enum SubpixelRendering {
-    SUBPIXEL_RENDERING_NONE = 0,
-    SUBPIXEL_RENDERING_RGB,
-    SUBPIXEL_RENDERING_BGR,
-    SUBPIXEL_RENDERING_VRGB,
-    SUBPIXEL_RENDERING_VBGR,
-  };
-
-  // Antialiasing (grayscale if |subpixel_rendering| is SUBPIXEL_RENDERING_NONE
-  // and RGBA otherwise).
-  bool antialiasing;
-
-  // Should subpixel positioning (i.e. fractional X positions for glyphs) be
-  // used?
-  bool subpixel_positioning;
-
-  // Should FreeType's autohinter be used (as opposed to Freetype's bytecode
-  // interpreter, which uses fonts' own hinting instructions)?
-  bool autohinter;
-
-  // Should embedded bitmaps in fonts should be used?
-  bool use_bitmaps;
-
-  // Hinting level.
-  Hinting hinting;
-
-  // Whether subpixel rendering should be used or not, and if so, the display's
-  // subpixel order.
-  SubpixelRendering subpixel_rendering;
-};
-
-// Returns the system's default parameters for font rendering.
-GFX_EXPORT const FontRenderParams& GetDefaultFontRenderParams();
-
-// Returns the system's default parameters for WebKit font rendering.
-GFX_EXPORT const FontRenderParams& GetDefaultWebKitFontRenderParams();
-
-// Returns the system's default parameters for WebKit subpixel positioning.
-// Subpixel positioning is special since neither GTK nor FontConfig currently
-// track it as a preference.
-// See https://bugs.freedesktop.org/show_bug.cgi?id=50736
-GFX_EXPORT bool GetDefaultWebkitSubpixelPositioning();
-
-}  // namespace gfx
-
-#endif  // UI_GFX_FONT_RENDER_PARAMS_LINUX_H_