ozone: Introduce ClientPixmap and ClientPixmapFactory for non-GPU processes.

ui/ozone/platform/drm/common/native_pixmap_manager_gbm.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/platform/drm/common/native_pixmap_manager_gbm.h"
+
+namespace ui {
+
+NativePixmapManager* CreateNativePixmapManagerGbm() {
+  return new NativePixmapManagerGbm();
+}
+
+NativePixmapManagerGbm::NativePixmapManagerGbm() {}
+
+NativePixmapManagerGbm::~NativePixmapManagerGbm() {}
+
+void NativePixmapManagerGbm::Initialize(const base::FileDescriptor& device_fd) {
+}
+
+std::vector<NativePixmapManager::Configuration>
+NativePixmapManagerGbm::GetSupportedNativePixmapConfigurations() const {
+  std::vector<Configuration> configurations = {
+      {SurfaceFactoryOzone::BGRA_8888, SurfaceFactoryOzone::SCANOUT},
+      {SurfaceFactoryOzone::RGBX_8888, SurfaceFactoryOzone::SCANOUT}};
+  return configurations;
+}
+
+}  // namespace ui