Move NumberOfPlanesForGpuMemoryBufferFormat to gfx

ui/gfx/buffer_format_util.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_GFX_BUFFER_FORMAT_UTIL_H_
+#define UI_GFX_BUFFER_FORMAT_UTIL_H_
+
+#include "base/basictypes.h"
+#include "ui/gfx/buffer_types.h"
+#include "ui/gfx/gfx_export.h"
+
+namespace gfx {
+
+// Returns the number of planes for |format|.
+GFX_EXPORT size_t NumberOfPlanesForBufferFormat(BufferFormat format);
+
+}  // namespace gfx
+
+#endif  // UI_GFX_BUFFER_FORMAT_UTIL_H_