NotForReview: Implement zero/one-copy texture for ozone freon using Intel DRM

ui/ozone/platform/drm/gpu/drm_intel_buffer_manager.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 "ui/ozone/public/platform/drm_intel_buffer_manager.h"
+
+extern "C" {
+#include <libdrm/intel_bufmgr.h>
+}
+
+#include "base/files/scoped_file.h"
+
+namespace ui {
+
+DrmIntelBufferManager::DrmIntelBufferManager() : buffer_manager_(nullptr) {
+}
+
+DrmIntelBufferManager::~DrmIntelBufferManager() {
+  if (buffer_manager_)
+    drm_intel_bufmgr_destroy(buffer_manager_);
+  if (device_fd_.auto_close)
+    base::ScopedFD closing_fd(device_fd_.fd);
+}
+
+bool DrmIntelBufferManager::Initialize(const base::FileDescriptor& device_fd) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (buffer_manager_)
+    return true;
+
+  device_fd_ = device_fd;
+
+  // TODO(dshwang): drm bufmgr doesn't need an execbuffer, so batch size is 0.
+  const int kBatchSize = 16 * 4096;
+  buffer_manager_ = drm_intel_bufmgr_gem_init(device_fd_.fd, kBatchSize);
+  if (!buffer_manager_) {
+    DLOG(ERROR) << "drm_intel_bufmgr_gem_init failed.";
+    return false;
+  }
+  return true;
+}
+
+drm_intel_bufmgr* DrmIntelBufferManager::buffer_manager() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return buffer_manager_;
+}
+
+int DrmIntelBufferManager::device_fd() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return device_fd_.fd;
+}
+
+}  // namespace ui