Fixes use after free during drag and drop.

chrome/browser/ui/views/frame/native_browser_frame_factory.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 "chrome/browser/ui/views/frame/native_browser_frame_factory.h"
+
+#include "chrome/browser/ui/views/frame/native_browser_frame.h"
+
+namespace {
+
+NativeBrowserFrameFactory* factory = NULL;
+
+}
+
+// static
+NativeBrowserFrame* NativeBrowserFrameFactory::CreateNativeBrowserFrame(
+    BrowserFrame* browser_frame,
+    BrowserView* browser_view) {
+  if (!factory)
+    factory = new NativeBrowserFrameFactory;
+  return factory->Create(browser_frame, browser_view);
+}
+
+// static
+void NativeBrowserFrameFactory::Set(NativeBrowserFrameFactory* new_factory) {
+  delete factory;
+  factory = new_factory;
+}