Introduces AppActivity and handler of chrome.shell API.

athena/content/content_app_model_builder.cc

Index: athena/content/content_app_model_builder.cc
diff --git a/athena/content/content_app_model_builder.cc b/athena/content/content_app_model_builder.cc
index 56bad7112bcc504630e0dac359365fd887e8bd31..116d72aec48627b59f079c567dd3e4821f21ebab 100644
--- a/athena/content/content_app_model_builder.cc
+++ b/athena/content/content_app_model_builder.cc
@@ -4,6 +4,7 @@
 
 #include "athena/content/public/content_app_model_builder.h"
 
+#include "apps/shell/browser/shell_extension_system.h"
 #include "athena/activity/public/activity_factory.h"
 #include "athena/activity/public/activity_manager.h"
 #include "ui/app_list/app_list_item.h"
@@ -36,9 +37,10 @@ class DummyItem : public app_list::AppListItem {
  private:
   // Overridden from app_list::AppListItem:
   virtual void Activate(int event_flags) OVERRIDE {
-    ActivityManager::Get()->AddActivity(
-        ActivityFactory::Get()->CreateAppActivity(
-            browser_context_, id_));
+    extensions::ShellExtensionSystem* extension_system =
+        static_cast<extensions::ShellExtensionSystem*>(
+            extensions::ExtensionSystem::Get(browser_context_));
+    extension_system->LaunchApp();
   }
 
   std::string id_;