- Factor platform-specific code out of CefBrowserHostImpl (issue #1749).

- Introduce native/ and osr/ folders for native (non-platform-agnostic) and
    osr (windowless) code respectively.
  - Introduce CefBrowserPlatformDelegate for abstracting platform-specific
    implementations of browser host functionality.
  - Move dialog and menu code to separate manager and platform-specific runner
    implementations exposed via CefBrowserPlatformDelegate.
  - Standardize focus-handling behavior between windowed and windowless
    implementations. CefFocusHandler::OnSetFocus() will now also be called for
    osr focus changes.
- Support multiple simultaneous popups (issue #1289).

libcef/browser/native/menu_runner_mac.h

@@ -0,0 +1,34 @@
+// Copyright (c) 2012 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that can
+// be found in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_NATIVE_MENU_RUNNER_MAC_H_
+#define CEF_LIBCEF_BROWSER_NATIVE_MENU_RUNNER_MAC_H_
+#pragma once
+
+#include "libcef/browser/menu_runner.h"
+
+#include "base/mac/scoped_nsobject.h"
+
+#if __OBJC__
+@class MenuController;
+#else
+class MenuController;
+#endif
+
+class CefMenuRunnerMac : public CefMenuRunner {
+ public:
+  CefMenuRunnerMac();
+  ~CefMenuRunnerMac() override;
+
+  // CefMenuRunner methods.
+  bool RunContextMenu(CefBrowserHostImpl* browser,
+                      ui::MenuModel* model,
+                      const content::ContextMenuParams& params) override;
+  void CancelContextMenu() override;
+
+ private:
+  base::scoped_nsobject<MenuController> menu_controller_;
+};
+
+#endif  // CEF_LIBCEF_BROWSER_NATIVE_MENU_RUNNER_MAC_H_