Use DSF instead of UI scale if the native DSF is 1.25 and UI Scale is 0.8x (dsf=1.25 equivalent)

ash/display/display_info.h

 // Copyright (c) 2013 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 ASH_DISPLAY_DISPLAY_INFO_H_
 #define ASH_DISPLAY_DISPLAY_INFO_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 76 matching lines @@
 
   DisplayInfo();
   DisplayInfo(int64 id, const std::string& name, bool has_overscan);
   ~DisplayInfo();
 
   // When this is set to true, Chrome switches High DPI when lower UI scale
   // (<1.0f) is specified on 1x device to make UI sharp, e.g, upgrade 0.6
   // scale on 1x DSF to 1.2 scale on 2x DSF.
   static void SetAllowUpgradeToHighDPI(bool enable);
 
+  // When this is set to true on the device whose internal display has
+  // 1.25 dsf, Chrome uses 1.0f as a default scale factor, and uses
+  // dsf 1.25 when UI scaling is set to 0.8f.
+  static void SetUse125DSFForUIScaling(bool enable);
+
   int64 id() const { return id_; }
 
   // The name of the display.
   const std::string& name() const { return name_; }
 
   // True if the display EDID has the overscan flag. This does not create the
   // actual overscan automatically, but used in the message.
   bool has_overscan() const { return has_overscan_; }
 
   void set_rotation(gfx::Display::Rotation rotation) { rotation_ = rotation; }
@@ skipping 156 matching lines @@
   // The current profile of the color calibration.
   ui::ColorCalibrationProfile color_profile_;
 
   // The list of available variations for the color calibration.
   std::vector<ui::ColorCalibrationProfile> available_color_profiles_;
 };
 
 }  // namespace ash
 
 #endif  //  ASH_DISPLAY_DISPLAY_INFO_H_