Add FontRenderParamsQuery.

ui/gfx/font_render_params.h

 // Copyright 2014 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_H_
 #define UI_GFX_FONT_RENDER_PARAMS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 22 matching lines @@
     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?
+  // TODO(derat): Remove this; we don't set it in the browser and mostly ignore
+  // it in Blink: http://crbug.com/396659
   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();
+// A query used to determine the appropriate FontRenderParams.
+struct GFX_EXPORT FontRenderParamsQuery {
+  explicit FontRenderParamsQuery(bool for_web_contents);
+  ~FontRenderParamsQuery();
 
-// Returns the system's default parameters for WebKit font rendering.
-// TODO(derat): Rename to GetDefaultFontRenderParamsForWebContents().
-GFX_EXPORT const FontRenderParams& GetDefaultWebKitFontRenderParams();
+  bool is_empty() const {
+    return families.empty() && pixel_size <= 0 && point_size <= 0 && style < 0;
+  }
 
-// Returns the appropriate parameters for rendering the font described by the
-// passed-in-arguments, any of which may be NULL. If |family_out| is non-NULL,
-// it will be updated to contain the recommended font family from |family_list|.
-// |style| optionally points to a bit field of Font::FontStyle values.
-GFX_EXPORT FontRenderParams GetCustomFontRenderParams(
-    bool for_web_contents,
-    const std::vector<std::string>* family_list,
-    const int* pixel_size,
-    const int* point_size,
-    const int* style,
+  // True if rendering text for the web.
+  // TODO(derat): Remove this once FontRenderParams::subpixel_positioning is
+  // gone: http://crbug.com/396659
+  bool for_web_contents;
+
+  // Requested font families, or empty if unset.
+  std::vector<std::string> families;
+
+  // Font size in pixels or points, or 0 if unset.
+  int pixel_size;
+  int point_size;
+
+  // gfx::Font::FontStyle bit field, or -1 if unset.
+  int style;
+};
+
+// Returns the appropriate parameters for rendering the font described by
+// |query|. If |family_out| is non-NULL, it will be updated to contain the
+// recommended font family from |query.families|.
+GFX_EXPORT FontRenderParams GetFontRenderParams(
+    const FontRenderParamsQuery& query,
     std::string* family_out);
 
 }  // namespace gfx
 
 #endif  // UI_GFX_FONT_RENDER_PARAMS_H_