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

ui/ozone/public/client_native_pixmap.h

+// 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.
+
+#ifndef UI_OZONE_PUBLIC_CLIENT_NATIVE_PIXMAP_H_
+#define UI_OZONE_PUBLIC_CLIENT_NATIVE_PIXMAP_H_
+
+#include "ui/ozone/ozone_export.h"
+
+namespace ui {
+
+// This represents a buffer that can be written to directly by regular CPU code,
+// but can also be read by the GPU.
+// NativePixmap is its counterpart in GPU process.
+class OZONE_EXPORT ClientNativePixmap {
+ public:
+  virtual ~ClientNativePixmap() {}
+
+  virtual bool Map(void** data) = 0;
+  virtual void Unmap() = 0;
+  virtual void GetStride(int* stride) const = 0;
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PUBLIC_CLIENT_NATIVE_PIXMAP_H_