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

Index: ash/display/display_info.h
diff --git a/ash/display/display_info.h b/ash/display/display_info.h
index adcf0482aed59533bd4e94a8afca7b5708d3eed9..a7db7f06a2c14acecf756d0e45187170f4f8c5a5 100644
--- a/ash/display/display_info.h
+++ b/ash/display/display_info.h
@@ -94,6 +94,11 @@ class ASH_EXPORT DisplayInfo {
   // 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);

[Jun Mukai, 2014/09/16 15:41:10]

nobody seems to call this.  how does this get enabled in the real environment?

[oshima, 2014/09/16 15:59:41]

I'll land it as separate CL. The plan is to land and merge this, and then
land CL to enable it on ToT, and then merge it after last m38 beta.

+
   int64 id() const { return id_; }
 
   // The name of the display.