Change namespace from ui to gfx for NativePixmap related code

ui/gl/gl_image_native_pixmap.h

 // Copyright 2016 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_GL_GL_IMAGE_NATIVE_PIXMAP_H_
 #define UI_GL_GL_IMAGE_NATIVE_PIXMAP_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "ui/gfx/native_pixmap.h"
 #include "ui/gl/gl_export.h"
 #include "ui/gl/gl_image_egl.h"
 
-namespace ui {
+namespace gl {
 
 class GL_EXPORT GLImageNativePixmap : public gl::GLImageEGL {
  public:
   GLImageNativePixmap(const gfx::Size& size, unsigned internalformat);
 
-  bool Initialize(NativePixmap* pixmap, gfx::BufferFormat format);
+  bool Initialize(gfx::NativePixmap* pixmap, gfx::BufferFormat format);
 
   // Overridden from GLImage:
   unsigned GetInternalFormat() override;
   bool CopyTexImage(unsigned target) override;
   bool ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
                             int z_order,
                             gfx::OverlayTransform transform,
                             const gfx::Rect& bounds_rect,
                             const gfx::RectF& crop_rect) override;
   void Flush() override;
   void OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd,
                     uint64_t process_tracing_id,
                     const std::string& dump_name) override;
 
   static unsigned GetInternalFormatForTesting(gfx::BufferFormat format);
 
  protected:
   ~GLImageNativePixmap() override;
 
  private:
   unsigned internalformat_;
-  scoped_refptr<NativePixmap> pixmap_;
+  scoped_refptr<gfx::NativePixmap> pixmap_;
   bool has_image_flush_external_;
 };
 
-}  // namespace ui
+}  // namespace gl
 
 #endif  // UI_GL_GL_IMAGE_NATIVE_PIXMAP_H_