Only Call EnableChildWindowDpiMessage When Window Has A Frame

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 9b40b5089d88dca57f1a446cb805ed2431a6d7e1..ab5b7ab25d9b903d0619d32c635e6a65acc6f0ad 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -349,6 +349,20 @@ void HWNDMessageHandler::Init(HWND parent, const gfx::Rect& bounds) {
   // Create the window.
   WindowImpl::Init(parent, bounds);
 
+  if (delegate_->HasFrame() && base::win::IsProcessPerMonitorDpiAware()) {
+    static auto enable_child_window_dpi_message_func = []() {
+      // Derived signature; not available in headers.
+      // This call gets Windows to scale the non-client area when WM_DPICHANGED
+      // is fired.
+      using EnableChildWindowDpiMessagePtr = LRESULT (WINAPI*)(HWND, BOOL);
+      return reinterpret_cast<EnableChildWindowDpiMessagePtr>(
+                 GetProcAddress(GetModuleHandle(L"user32.dll"),
+                                "EnableChildWindowDpiMessage"));
+    }();
+    if (enable_child_window_dpi_message_func)
+      enable_child_window_dpi_message_func(hwnd(), TRUE);
+  }
+
   prop_window_target_.reset(new ui::ViewProp(hwnd(),
                             ui::WindowEventTarget::kWin32InputEventTarget,
                             static_cast<ui::WindowEventTarget*>(this)));