Move ContentAppModelBuilder to athena/extensions.

athena/content/public/content_app_model_builder.h

-// 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.
-
-#ifndef ATHENA_CONTENT_PUBLIC_CONTENT_APP_MODEL_BUILDER_H_
-#define ATHENA_CONTENT_PUBLIC_CONTENT_APP_MODEL_BUILDER_H_
-
-#include "athena/home/public/app_model_builder.h"
-#include "base/macros.h"
-
-namespace content {
-class BrowserContext;
-}
-
-namespace athena {
-
-class ATHENA_EXPORT ContentAppModelBuilder : public AppModelBuilder {
- public:
-  explicit ContentAppModelBuilder(content::BrowserContext* browser_context);
-  virtual ~ContentAppModelBuilder();
-
-  virtual void PopulateApps(app_list::AppListModel* model) OVERRIDE;
-
- private:
-  content::BrowserContext* browser_context_;
-
-  DISALLOW_COPY_AND_ASSIGN(ContentAppModelBuilder);
-};
-
-}  // namespace athena
-
-#endif  // ATHENA_CONTENT_PUBLIC_CONTENT_APP_MODEL_BUILDER_H_