Enable subpixel positioning for internal display with dsf larger than 1.0

ui/gfx/font_render_params.h

Index: ui/gfx/font_render_params.h
diff --git a/ui/gfx/font_render_params.h b/ui/gfx/font_render_params.h
index cd7c0a45115c3d7fb364768a31cced9cf9eb4232..4ec8d3502f15a2981f179b9fb02547a942743e3a 100644
--- a/ui/gfx/font_render_params.h
+++ b/ui/gfx/font_render_params.h
@@ -98,6 +98,13 @@ GFX_EXPORT FontRenderParams GetFontRenderParams(
 // out what's going on here.
 GFX_EXPORT void ClearFontRenderParamsCacheForTest();
 
+#if defined(OS_CHROMEOS)
+// Sets the device scale factor for FontRenderParams to decide
+// if it should enable subpixel positioning.
+GFX_EXPORT void SetFontRenderParamsDeviceScaleFactor(
+    float device_scale_factor);
+#endif
+
 }  // namespace gfx
 
 #endif  // UI_GFX_FONT_RENDER_PARAMS_H_