Fixes crash in closing menus. There are two issues here:

ui/views/widget/native_widget_win.cc

Index: ui/views/widget/native_widget_win.cc
diff --git a/ui/views/widget/native_widget_win.cc b/ui/views/widget/native_widget_win.cc
index ede049e6e11767a0bf57947d692050ca3158dc63..216b1fba752e05cca8a8d885b1da496397fc78cc 100644
--- a/ui/views/widget/native_widget_win.cc
+++ b/ui/views/widget/native_widget_win.cc
@@ -321,6 +321,21 @@ const int kCustomObjectID = 1;
 
 const int kDragFrameWindowAlpha = 200;
 
+struct FindOwnedWindowsData {
+  HWND window;
+  std::vector<Widget*> owned_widgets;
+};
+
+BOOL CALLBACK FindOwnedWindowsCallback(HWND hwnd, LPARAM param) {
+  FindOwnedWindowsData* data = reinterpret_cast<FindOwnedWindowsData*>(param);
+  if (GetWindow(hwnd, GW_OWNER) == data->window) {
+    Widget* widget = Widget::GetWidgetForNativeView(hwnd);
+    if (widget)
+      data->owned_widgets.push_back(widget);
+  }
+  return TRUE;
+}
+
 }  // namespace
 
 // static
@@ -891,6 +906,9 @@ void NativeWidgetWin::Hide() {
     SetWindowPos(NULL, 0, 0, 0, 0,
                  SWP_HIDEWINDOW | SWP_NOACTIVATE | SWP_NOMOVE |
                  SWP_NOREPOSITION | SWP_NOSIZE | SWP_NOZORDER);
+
+    if (!GetParent())
+      NotifyOwnedWindowsParentClosing();

[oshima, 2012/04/26 03:05:27]

Can a widget be closed by Windows?

[sky, 2012/04/26 03:54:53]

Do you mean can windows close out from under us? Yes. There is nothing stopping
windows or another app from closing an app window.

   }
 }
 
@@ -2486,6 +2504,15 @@ void NativeWidgetWin::RestoreEnabledIfNecessary() {
   }
 }
 
+void NativeWidgetWin::NotifyOwnedWindowsParentClosing() {
+  FindOwnedWindowsData data;
+  data.window = hwnd();
+  EnumThreadWindows(GetCurrentThreadId(), FindOwnedWindowsCallback,
+                    reinterpret_cast<LPARAM>(&data));
+  for (size_t i = 0; i < data.owned_widgets.size(); ++i)
+    data.owned_widgets[i]->OnOwnedParentClosing();
+}
+
 void NativeWidgetWin::DispatchKeyEventPostIME(const KeyEvent& key) {
   SetMsgHandled(delegate_->OnKeyEvent(key));
 }