Revert of Move fetching logic out of ApplicationManager, eliminate url mappings.

mojo/fetcher/base_application_fetcher.h

-// Copyright 2015 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.
-
-#include "base/files/file_path.h"
-#include "mojo/fetcher/url_resolver.h"
-#include "mojo/services/network/public/interfaces/network_service.mojom.h"
-#include "mojo/services/network/public/interfaces/url_loader_factory.mojom.h"
-#include "mojo/shell/application_fetcher.h"
-
-namespace mojo {
-namespace fetcher {
-
-// This is the default implementation of shell::ApplicationFetcher. It loads
-// http/s urls off the network as well as providing special handling for mojo:
-// and about: urls.
-class BaseApplicationFetcher : public shell::ApplicationFetcher {
- public:
-  // mojo: urls are only supported if |shell_file_root| is non-empty.
-  BaseApplicationFetcher(const base::FilePath& shell_file_root);
-  ~BaseApplicationFetcher() override;
-
- private:
-  // Overridden from shell::ApplicationFetcher:
-  void SetApplicationManager(shell::ApplicationManager* manager) override;
-  GURL ResolveURL(const GURL& url) override;
-  void FetchRequest(
-      URLRequestPtr request,
-      const shell::Fetcher::FetchCallback& loader_callback) override;
-
-  shell::ApplicationManager* application_manager_;
-  scoped_ptr<URLResolver> url_resolver_;
-  const bool disable_cache_;
-  NetworkServicePtr network_service_;
-  URLLoaderFactoryPtr url_loader_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(BaseApplicationFetcher);
-};
-
-}  // namespace fetcher
-}  // namespace mojo