Making ShowExtensionInstallDialog a callback

chrome/browser/ui/android/extensions/extension_install_dialog_android.cc

 // Copyright (c) 2012 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/extensions/extension_install_dialog.h"
+#include "base/bind.h"
+#include "chrome/browser/extensions/extension_install_prompt.h"
+
+namespace {
 
 void ShowExtensionInstallDialogImpl(
     gfx::NativeWindow parent,
     content::PageNavigator* navigator,
     ExtensionInstallPrompt::Delegate* delegate,
     const ExtensionInstallPrompt::Prompt& prompt) {
   NOTIMPLEMENTED();
 }
 
+}  // namespace
+
+// static
+ExtensionInstallPrompt::ShowDialogCallback
+ExtensionInstallPrompt::GetDefaultShowDialogCallback() {
+  return base::Bind(&ShowExtensionInstallDialogImpl);
+}