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 7e414e7ef59cdbb40d1d4ce7870b88b7f4ae74ce..5b9b1d756cf3fa0b74662b4dc76d074ad579ef8b 100644
--- a/athena/content/shell/shell_app_activity.cc
+++ b/athena/content/shell/shell_app_activity.cc
@@ -4,19 +4,30 @@
 
 #include "athena/content/shell/shell_app_activity.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"
 
 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_|.
 }
 
 content::WebContents* ShellAppActivity::GetWebContents() {
+  if (app_window_)
+    return app_window_->web_contents();
+  DCHECK(shell_app_window_);
   return shell_app_window_->GetAssociatedWebContents();
 }