Fixed tab dragging which was broken on high DPI windows for scales other than 100%.

ui/gfx/screen_win.cc

Index: ui/gfx/screen_win.cc
diff --git a/ui/gfx/screen_win.cc b/ui/gfx/screen_win.cc
index 845249a335304b023b989636fca219321a00e8af..0da5833a0c9c143b688619204d47079dfa6ceef1 100644
--- a/ui/gfx/screen_win.cc
+++ b/ui/gfx/screen_win.cc
@@ -65,7 +65,8 @@ bool ScreenWin::IsDIPEnabled() {
 gfx::Point ScreenWin::GetCursorScreenPoint() {
   POINT pt;
   GetCursorPos(&pt);
-  return gfx::Point(pt);
+  gfx::Point cursor_pos_pixels(pt);
+  return gfx::win::ScreenToDIPPoint(cursor_pos_pixels);
 }
 
 gfx::NativeWindow ScreenWin::GetWindowUnderCursor() {