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

ui/ozone/public/client_pixmap_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/client_pixmap_manager.h"
+
+#include "base/trace_event/trace_event.h"
+#include "ui/ozone/platform_object.h"
+#include "ui/ozone/platform_selection.h"
+
+namespace ui {
+
+namespace {
+
+ClientPixmapManager* g_instance = nullptr;
+
+}  // namespace
+
+// static
+ClientPixmapManager* ClientPixmapManager::GetInstance() {
+  return g_instance;
+}
+
+// static
+void ClientPixmapManager::SetInstance(ClientPixmapManager* instance) {
+  DCHECK(!g_instance);
+  DCHECK(instance);
+  g_instance = instance;
+}
+
+// static
+scoped_ptr<ClientPixmapManager> ClientPixmapManager::Create() {
+  TRACE_EVENT1("ozone", "ClientPixmapManager::Create", "platform",
+               GetOzonePlatformName());
+  return PlatformObject<ClientPixmapManager>::Create();
+}
+
+ClientPixmapManager::ClientPixmapManager() {}
+
+ClientPixmapManager::~ClientPixmapManager() {}
+
+}  // namespace ui