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_