Remove some implicit Point to PointF conversions, add helpers.

ui/wm/core/default_screen_position_client.cc

Index: ui/wm/core/default_screen_position_client.cc
diff --git a/ui/wm/core/default_screen_position_client.cc b/ui/wm/core/default_screen_position_client.cc
index c9dadc826951149ab6f1d9bc2ec7e60aea670cad..d26a91ed9c8f92c66495eab9cfc7de7e5a749d87 100644
--- a/ui/wm/core/default_screen_position_client.cc
+++ b/ui/wm/core/default_screen_position_client.cc
@@ -23,7 +23,7 @@ gfx::Point DefaultScreenPositionClient::GetOriginInScreen(
   aura::Window* window = const_cast<aura::Window*>(root_window);
   float scale = gfx::Screen::GetScreenFor(window)->
        GetDisplayNearestWindow(window).device_scale_factor();
-  return gfx::ToFlooredPoint(gfx::ScalePoint(origin_in_pixels, 1.0f / scale));
+  return gfx::ScaleToFlooredPoint(origin_in_pixels, 1.0f / scale);
 }
 
 void DefaultScreenPositionClient::ConvertPointToScreen(