Use actual value of display scale factor from GetMonitorScaleFactor().

ui/views/win/hwnd_message_handler.cc

Index: ui/views/win/hwnd_message_handler.cc
diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index 020d0a1f9e06a46b1e80c081bb01d338c22a004e..55fc05dfc9ab3e0d101cf420fbb99228013eee52 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -1418,6 +1418,8 @@ LRESULT HWNDMessageHandler::OnDpiChanged(UINT msg,
   SetBoundsInternal(gfx::Rect(*reinterpret_cast<RECT*>(l_param)), false);
   delegate_->HandleWindowScaleFactorChanged(
       display::win::GetScalingFactorFromDPI(dpi_));
+
+  LOG(ERROR) << "HWNDMessageHandler::OnDpiChanged(" << dpi << ")";
   return 0;
 }