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

mojo/runner/about_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.
+
+#ifndef MOJO_RUNNER_ABOUT_FETCHER_H_
+#define MOJO_RUNNER_ABOUT_FETCHER_H_
+
+#include "mojo/shell/fetcher.h"
+
+#include "base/macros.h"
+#include "mojo/services/network/public/interfaces/url_loader.mojom.h"
+#include "url/gurl.h"
+
+namespace mojo {
+namespace runner {
+
+// Implements Fetcher for about: URLs.
+class AboutFetcher : public shell::Fetcher {
+ public:
+  static const char kAboutScheme[];
+  static const char kAboutBlankURL[];
+
+  static void Start(const GURL& url, const FetchCallback& loader_callback);
+
+ private:
+  AboutFetcher(const GURL& url, const FetchCallback& loader_callback);
+  ~AboutFetcher() override;
+
+  void BuildResponse();
+
+  // Must be called exactly once to run the loader callback (asynchrously). On
+  // success, the ownership of this object is passed to the loader callback;
+  // otherwise, the callback is run with a nullptr and this object is destroyed.
+  void PostToRunCallback(bool success);
+
+  // shell::Fetcher implementation.
+  const GURL& GetURL() const override;
+  GURL GetRedirectURL() const override;
+  GURL GetRedirectReferer() const override;
+  URLResponsePtr AsURLResponse(base::TaskRunner* task_runner,
+                               uint32_t skip) override;
+  void AsPath(
+      base::TaskRunner* task_runner,
+      base::Callback<void(const base::FilePath&, bool)> callback) override;
+  std::string MimeType() override;
+  bool HasMojoMagic() override;
+  bool PeekFirstLine(std::string* line) override;
+
+  const GURL url_;
+  URLResponsePtr response_;
+
+  DISALLOW_COPY_AND_ASSIGN(AboutFetcher);
+};
+
+}  // namespace runner
+}  // namespace mojo
+
+#endif  // MOJO_RUNNER_ABOUT_FETCHER_H_