[Win] Update HWND style when SizeConstraintsChanged.

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 d726ea930d98d95feceb2da247503f41c5fabb27..e5b3bd50b514d8acbaf810e9a7d644ed536045e5 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -868,6 +868,23 @@ void HWNDMessageHandler::SetFullscreen(bool fullscreen) {
     PerformDwmTransition();
 }
 
+void HWNDMessageHandler::SizeConstraintsChanged() {
+  bool can_resize = delegate_->CanResize();
+  bool can_maximize = delegate_->CanMaximize();
+  LONG style = GetWindowLong(hwnd(), GWL_STYLE);
+  if (can_resize && can_maximize) {
+    style |= WS_MINIMIZEBOX | WS_MAXIMIZEBOX;
+  } else {
+    style &= ~(WS_MINIMIZEBOX | WS_MAXIMIZEBOX);
+  }
+  if (can_resize) {
+    style |= WS_THICKFRAME;
+  } else {
+    style &= ~WS_THICKFRAME;
+  }
+  SetWindowLong(hwnd(), GWL_STYLE, style);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // HWNDMessageHandler, InputMethodDelegate implementation: