MacViewsBrowser: Provide a stub for ChromeExtensionChooserDialog::ShowDialog()

chrome/browser/ui/bluetooth/chrome_extension_bluetooth_chooser.cc

 // Copyright 2016 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/bluetooth/chrome_extension_bluetooth_chooser.h"
 
 #include "chrome/browser/extensions/chrome_extension_chooser_dialog.h"
 #include "chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h"
 #include "content/public/browser/web_contents.h"
 
 ChromeExtensionBluetoothChooser::ChromeExtensionBluetoothChooser(
     content::RenderFrameHost* frame,
     const content::BluetoothChooser::EventHandler& event_handler) {
   bluetooth_chooser_controller_.reset(
       new BluetoothChooserController(frame, event_handler));
   chooser_dialog_.reset(new ChromeExtensionChooserDialog(
       content::WebContents::FromRenderFrameHost(frame)));
-#if defined(OS_MACOSX)
   chooser_dialog_->ShowDialog(bluetooth_chooser_controller_.get());
-#endif  // defined(OS_MACOSX)
 }
 
 ChromeExtensionBluetoothChooser::~ChromeExtensionBluetoothChooser() {}
 
 void ChromeExtensionBluetoothChooser::SetAdapterPresence(
     AdapterPresence presence) {}
 
 void ChromeExtensionBluetoothChooser::ShowDiscoveryState(DiscoveryState state) {
 }
 
 void ChromeExtensionBluetoothChooser::AddDevice(
     const std::string& device_id,
     const base::string16& device_name) {
   bluetooth_chooser_controller_->AddDevice(device_id, device_name);
 }
 
 void ChromeExtensionBluetoothChooser::RemoveDevice(
     const std::string& device_id) {
   bluetooth_chooser_controller_->RemoveDevice(device_id);
 }