Sandbox html_viewer on Linux.

components/font_service/public/cpp/mapped_font_file.cc

+// 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 "components/font_service/public/cpp/mapped_font_file.h"
+
+#include "base/files/file_util.h"
+#include "base/threading/thread_restrictions.h"
+#include "skia/ext/refptr.h"
+#include "skia/ext/skia_utils_base.h"
+#include "third_party/skia/include/core/SkData.h"
+#include "third_party/skia/include/core/SkStream.h"
+
+namespace font_service {
+namespace internal {
+
+MappedFontFile::MappedFontFile(uint32_t font_id)
+    : font_id_(font_id), observer_(nullptr) {}
+
+bool MappedFontFile::Initialize(base::File file) {
+  base::ThreadRestrictions::ScopedAllowIO allow_mmap;
+  return mapped_font_file_.Initialize(file.Pass());
+}
+
+SkMemoryStream* MappedFontFile::CreateMemoryStream() {
+  DCHECK(mapped_font_file_.IsValid());
+  auto data = skia::AdoptRef(
+      SkData::NewWithProc(mapped_font_file_.data(), mapped_font_file_.length(),
+                          &MappedFontFile::ReleaseProc, this));
+  if (!data)
+    return nullptr;
+  AddRef();
+  return new SkMemoryStream(data.get());
+}
+
+MappedFontFile::~MappedFontFile() {
+  if (observer_)
+    observer_->OnMappedFontFileDestroyed(this);
+}
+
+// static
+void MappedFontFile::ReleaseProc(const void* ptr, void* context) {
+  base::ThreadRestrictions::ScopedAllowIO allow_munmap;
+  static_cast<MappedFontFile*>(context)->Release();
+}
+
+}  // namespace internal
+}  // namespace font_service