Support app.window.create on athena

athena/content/shell/shell_app_activity.cc

Index: athena/content/shell/shell_app_activity.cc
diff --git a/athena/content/shell/shell_app_activity.cc b/athena/content/shell/shell_app_activity.cc
index d8a507737735c53a30fb4767758daef5adccce2b..50eb45b6e4804f855aea7a9ef45ad9f1f8c570b7 100644
--- a/athena/content/shell/shell_app_activity.cc
+++ b/athena/content/shell/shell_app_activity.cc
@@ -5,17 +5,25 @@
 #include "athena/content/shell/shell_app_activity.h"
 
 #include "content/public/browser/web_contents.h"
+#include "extensions/browser/app_window/app_window.h"
+#include "extensions/browser/app_window/native_app_window.h"
 #include "extensions/shell/browser/shell_app_window.h"
 #include "ui/views/controls/webview/webview.h"
 
 namespace athena {
 
+ShellAppActivity::ShellAppActivity(extensions::AppWindow* app_window)
+    : AppActivity(app_window->extension_id()), app_window_(app_window) {
+}
+
 ShellAppActivity::ShellAppActivity(extensions::ShellAppWindow* app_window,
                                    const std::string& app_id)
-    : AppActivity(app_id), shell_app_window_(app_window) {
+    : AppActivity(app_id), app_window_(NULL), shell_app_window_(app_window) {
 }
 
 ShellAppActivity::~ShellAppActivity() {
+  if (app_window_)
+    app_window_->GetBaseWindow()->Close();  // Deletes |app_window_|.
 }
 
 views::Widget* ShellAppActivity::CreateWidget() {
@@ -24,6 +32,7 @@ views::Widget* ShellAppActivity::CreateWidget() {
 
 views::WebView* ShellAppActivity::GetWebView() {
   content::WebContents* web_contents =
+      app_window_ ? app_window_->web_contents() :
       shell_app_window_->GetAssociatedWebContents();
   views::WebView* web_view =
       new views::WebView(web_contents->GetBrowserContext());