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

extensions/shell/browser/shell_app_window_client.cc

Index: extensions/shell/browser/shell_app_window_client.cc
diff --git a/extensions/shell/browser/shell_app_window_client.cc b/extensions/shell/browser/shell_app_window_client.cc
index 293f58b91c7dc427f5c2bc6f0638ef2a2daafaad..08ac1c58b1c1edefa713ab2c553da16d5e4ee904 100644
--- a/extensions/shell/browser/shell_app_window_client.cc
+++ b/extensions/shell/browser/shell_app_window_client.cc
@@ -8,7 +8,10 @@
 
 #include "extensions/browser/app_window/app_window.h"
 #include "extensions/shell/browser/desktop_controller.h"
-#include "extensions/shell/browser/shell_native_app_window.h"
+
+#if defined(USE_AURA)
+#include "extensions/shell/browser/shell_native_app_window_aura.h"
+#endif
 
 namespace extensions {
 
@@ -24,15 +27,17 @@ AppWindow* ShellAppWindowClient::CreateAppWindow(
   return DesktopController::instance()->CreateAppWindow(context, extension);
 }
 
+#if defined(USE_AURA)
 NativeAppWindow* ShellAppWindowClient::CreateNativeAppWindow(
       AppWindow* window,
       AppWindow::CreateParams* params) {
   ShellNativeAppWindow* native_app_window =
-      new ShellNativeAppWindow(window, *params);
+      new ShellNativeAppWindowAura(window, *params);
   DesktopController::instance()->AddAppWindow(
       native_app_window->GetNativeWindow());
   return native_app_window;
 }
+#endif  // USE_AURA
 
 void ShellAppWindowClient::OpenDevToolsWindow(
     content::WebContents* web_contents,