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

ui/ozone/public/native_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/native_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 {
+
+NativePixmapManager* g_instance = nullptr;
+
+}  // namespace
+
+// static
+NativePixmapManager* NativePixmapManager::GetInstance() {
+  return g_instance;
+}
+
+// static
+void NativePixmapManager::SetInstance(
+    scoped_ptr<NativePixmapManager> instance) {
+  DCHECK(!g_instance);
+  DCHECK(instance);
+  g_instance = instance.release();
+}
+
+// static
+scoped_ptr<NativePixmapManager> NativePixmapManager::Create() {
+  TRACE_EVENT1("ozone", "NativePixmapManager::Create", "platform",
+               GetOzonePlatformName());
+  scoped_ptr<NativePixmapManager> manager =

[reveman, 2015/07/23 14:46:12]

just "return PlatformObject<NativePixmapManager>::Create();" instead?

[dshwang, 2015/07/23 16:42:09]

Done.

+      PlatformObject<NativePixmapManager>::Create();
+  return manager.Pass();
+}
+
+NativePixmapManager::NativePixmapManager() {}
+
+NativePixmapManager::~NativePixmapManager() {}
+
+}  // namespace ui