Remove screen dependency from font_render_params_linux

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 90 matching lines @@
 GFX_EXPORT FontRenderParams GetFontRenderParams(
     const FontRenderParamsQuery& query,
     std::string* family_out);
 
 #if defined(OS_LINUX)
 // Clears GetFontRenderParams()'s cache. Intended to be called by tests that are
 // changing Fontconfig's configuration.
 GFX_EXPORT void ClearFontRenderParamsCacheForTest();
 #endif
 
-#if defined(OS_CHROMEOS)
+#if defined(OS_CHROMEOS) || defined(OS_LINUX)

[msw, 2016/04/08 20:42:58]

nit: Isn't OS_LINUX true on OS_CHROMEOS? If so, you can remove the OS_CHROMEOS
check and merge this with the OS_LINUX block above.

[oshima, 2016/04/08 21:28:17]

That's technically true, although it still can be informative.

I don't have strong opinion and will follow the owner's recommendation as there
are other places that have this.

 // Gets the device scale factor to query the FontRenderParams.
-float GetFontRenderParamsDeviceScaleFactor();
+GFX_EXPORT float GetFontRenderParamsDeviceScaleFactor();
 
 // 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_