Handle floating point coordinates from ozone to exosphere

ui/aura/client/screen_position_client.h

Index: ui/aura/client/screen_position_client.h
diff --git a/ui/aura/client/screen_position_client.h b/ui/aura/client/screen_position_client.h
index f6d5ad950a5a4c916a20179e9dd1314916f3e451..4732e62ba22a5fbaf16f236fbac1ea602ac7ab57 100644
--- a/ui/aura/client/screen_position_client.h
+++ b/ui/aura/client/screen_position_client.h
@@ -29,6 +29,10 @@ class AURA_EXPORT ScreenPositionClient {
                                     gfx::Point* point) = 0;
   virtual void ConvertPointFromScreen(const Window* window,
                                       gfx::Point* point) = 0;
+  virtual void ConvertPointToScreenF(const Window* window,

[oshima, 2017/01/20 22:11:54]

I have a slight preference for ConvertPointFToScreen. I'll leave it to the owner
though.

+                                     gfx::PointF* point) = 0;
+  virtual void ConvertPointFromScreenF(const Window* window,
+                                       gfx::PointF* point) = 0;
   // Converts the |screen_point| from root window host's coordinate of
   // into screen coordinate space.
   // A typical example of using this function instead of ConvertPointToScreen is