Context menu on views must show on mouse down for non-WIN.

ui/views/widget/widget_deletion_observer.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/widget/widget_deletion_observer.h"
+
+#include "ui/views/widget/widget.h"
+
+namespace views {
+
+WidgetDeletionObserver::WidgetDeletionObserver(Widget* widget)
+    : widget_(widget) {
+  if (widget_)
+    widget_->AddObserver(this);
+}
+
+WidgetDeletionObserver::~WidgetDeletionObserver() {
+  CleanupWidget();
+}
+
+void WidgetDeletionObserver::OnWidgetDestroying(Widget* widget) {
+  CleanupWidget();
+}
+
+void WidgetDeletionObserver::CleanupWidget() {
+  if (widget_) {
+    widget_->RemoveObserver(this);
+    widget_ = NULL;
+  }
+}
+
+}  // namespace views