Sandbox html_viewer on Linux.

components/font_service/public/cpp/font_loader.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_FONT_LOADER_H_
+#define COMPONENTS_FONT_SERVICE_PUBLIC_CPP_FONT_LOADER_H_
+
+#include "base/containers/hash_tables.h"
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "components/font_service/public/cpp/mapped_font_file.h"
+#include "components/font_service/public/interfaces/font_service.mojom.h"
+#include "third_party/skia/include/core/SkStream.h"
+#include "third_party/skia/include/core/SkTypeface.h"
+#include "third_party/skia/include/ports/SkFontConfigInterface.h"
+
+namespace mojo {
+class ApplicationImpl;
+}
+
+namespace font_service {
+namespace internal {
+class FontServiceThread;
+}
+
+// FontConfig implementation for Skia which proxies to the font service to get
+// out of the sandbox. This methods of this class (as imposed by blink
+// requirements) may be called on any thread. (Because of this restriction,
+// also see the FontServiceThread class.)
+//
+// This is the mojo equivalent to content/common/font_config_ipc_linux.h
+class FontLoader : public SkFontConfigInterface,
+                   public internal::MappedFontFile::Observer {
+ public:
+  explicit FontLoader(mojo::ApplicationImpl* application_impl);
+  ~FontLoader() override;
+
+  // SkFontConfigInterface:
+  bool matchFamilyName(const char family_name[],
+                       SkTypeface::Style requested,
+                       FontIdentity* out_font_identifier,
+                       SkString* out_family_name,
+                       SkTypeface::Style* out_style) override;
+  SkStreamAsset* openStream(const FontIdentity& identity) override;
+
+ private:
+  // internal::MappedFontFile::Observer:
+  void OnMappedFontFileDestroyed(internal::MappedFontFile* f) override;
+
+  // Thread to own the mojo message pipe. Because FontLoader can be called on
+  // multiple threads, we create a dedicated thread to send and receive mojo
+  // message calls.
+  scoped_refptr<internal::FontServiceThread> thread_;
+
+  // Lock preventing multiple threads from opening font file and accessing
+  // |mapped_font_files_| map at the same time.
+  base::Lock lock_;
+
+  // Maps font identity ID to the memory-mapped file with font data.
+  base::hash_map<uint32_t, internal::MappedFontFile*> mapped_font_files_;
+
+  DISALLOW_COPY_AND_ASSIGN(FontLoader);
+};
+
+}  // namespace font_service
+
+#endif  // COMPONENTS_FONT_SERVICE_PUBLIC_CPP_FONT_LOADER_H_