Refactor ShellDesktopController and ShellNativeAppWindow to allow for non-aura implementations.

extensions/shell/browser/default_shell_browser_main_delegate.cc

 // Copyright 2014 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 "extensions/shell/browser/default_shell_browser_main_delegate.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/strings/string_tokenizer.h"
 #include "extensions/common/switches.h"
-#include "extensions/shell/browser/shell_desktop_controller.h"
 #include "extensions/shell/browser/shell_extension_system.h"
 
+#if defined(USE_AURA)
+#include "extensions/shell/browser/shell_desktop_controller_aura.h"
+#endif
+
 namespace extensions {
 
 DefaultShellBrowserMainDelegate::DefaultShellBrowserMainDelegate() {
 }
 
 DefaultShellBrowserMainDelegate::~DefaultShellBrowserMainDelegate() {
 }
 
 void DefaultShellBrowserMainDelegate::Start(
     content::BrowserContext* browser_context) {
@@ skipping 30 matching lines @@
   } else {
     LOG(ERROR) << "--" << switches::kLoadApps
                << " unset; boredom is in your future";
   }
 }
 
 void DefaultShellBrowserMainDelegate::Shutdown() {
 }
 
 DesktopController* DefaultShellBrowserMainDelegate::CreateDesktopController() {
-  return new ShellDesktopController();
+#if defined(USE_AURA)
+  return new ShellDesktopControllerAura();
+#else
+  return NULL;
+#endif
 }
 
 }  // namespace extensions