fix: update Windows' cache after changing window's style (#31021)

To enable/disable window resizing we set/unset WS_THICKFRAME style
flag on the window. Window's frame styles are cached so we need to
call SetWindowPos with the SWP_FRAMECHANGED flag set to update
cache properly.

shell/browser/native_window_views.cc

@@ -111,6 +111,11 @@ void FlipWindowStyle(HWND handle, bool on, DWORD flag) {
   else
     style &= ~flag;
   ::SetWindowLong(handle, GWL_STYLE, style);
+  // Window's frame styles are cached so we need to call SetWindowPos
+  // with the SWP_FRAMECHANGED flag to update cache properly.
+  ::SetWindowPos(handle, 0, 0, 0, 0, 0,  // ignored
+                 SWP_FRAMECHANGED | SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER |
+                     SWP_NOACTIVATE | SWP_NOOWNERZORDER);
 }
 
 gfx::Rect DIPToScreenRect(HWND hwnd, const gfx::Rect& pixel_bounds) {