Change namespace from ui to gfx for NativePixmap related code

ui/gfx/client_native_pixmap_factory.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_CLIENT_NATIVE_PIXMAP_FACTORY_H_
 #define UI_GFX_CLIENT_NATIVE_PIXMAP_FACTORY_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/files/scoped_file.h"
 #include "base/macros.h"
 #include "ui/gfx/buffer_types.h"
 #include "ui/gfx/client_native_pixmap.h"
 #include "ui/gfx/gfx_export.h"
 
 namespace gfx {
+
 struct NativePixmapHandle;
 class Size;
-}
-
-namespace ui {
 
 // The Ozone interface allows external implementations to hook into Chromium to
 // provide a client pixmap for non-GPU processes.
 class GFX_EXPORT ClientNativePixmapFactory {
  public:
   static ClientNativePixmapFactory* GetInstance();
   static void SetInstance(ClientNativePixmapFactory* instance);
 
   virtual ~ClientNativePixmapFactory();
 
   // Returns true if format/usage configuration is supported.
   virtual bool IsConfigurationSupported(gfx::BufferFormat format,
                                         gfx::BufferUsage usage) const = 0;
 
   // TODO(dshwang): implement it. crbug.com/475633
   // Import the native pixmap from |handle| to be used in non-GPU processes.
   // This function takes ownership of any file descriptors in |handle|.
   virtual std::unique_ptr<ClientNativePixmap> ImportFromHandle(
       const gfx::NativePixmapHandle& handle,
       const gfx::Size& size,
       gfx::BufferUsage usage) = 0;
 
  protected:
   ClientNativePixmapFactory();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ClientNativePixmapFactory);
 };
 
-}  // namespace ui
+}  // namespace gfx
 
 #endif  // UI_GFX_CLIENT_NATIVE_PIXMAP_FACTORY_H_