Revert of Sandbox html_viewer on Linux.

components/font_service/public/cpp/mapped_font_file.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 COMPONENTS_FONT_SERVICE_PUBLIC_CPP_MAPPED_FONT_FILE_H_
-#define COMPONENTS_FONT_SERVICE_PUBLIC_CPP_MAPPED_FONT_FILE_H_
-
-#include "base/files/file.h"
-#include "base/files/memory_mapped_file.h"
-#include "base/memory/ref_counted.h"
-#include "third_party/skia/include/core/SkStream.h"
-
-namespace font_service {
-namespace internal {
-
-// Owns the memory of the mmaped file that we get back from the font_service.
-//
-// This class is an implementation detail and shouldn't be used by consumers.
-class MappedFontFile : public base::RefCountedThreadSafe<MappedFontFile> {
- public:
-  class Observer {
-   public:
-    ~Observer() {}
-
-    // Called when a MappedFontFile is destroyed.
-    virtual void OnMappedFontFileDestroyed(MappedFontFile* f) = 0;
-  };
-
-  explicit MappedFontFile(uint32_t font_id);
-
-  uint32_t font_id() const { return font_id_; }
-
-  void set_observer(Observer* observer) { observer_ = observer; }
-
-  bool Initialize(base::File file);
-
-  SkMemoryStream* CreateMemoryStream();
-
- private:
-  friend class base::RefCountedThreadSafe<MappedFontFile>;
-
-  ~MappedFontFile();
-
-  static void ReleaseProc(const void* ptr, void* context);
-
-  uint32_t font_id_;
-  base::MemoryMappedFile mapped_font_file_;
-  Observer* observer_;
-};
-
-}  // namespace internal
-}  // namespace font_service
-
-#endif  // COMPONENTS_FONT_SERVICE_PUBLIC_CPP_MAPPED_FONT_FILE_H_