Move code in ui/gl/* from gfx:: to gl::

ui/gl/scoped_api.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_GL_SCOPED_API_H_
 #define UI_GL_SCOPED_API_H_
 
 #include "base/macros.h"
 #include "ui/gl/gl_export.h"
 
-namespace gfx {
+namespace gl {
 
 class GLApi;
 
 class GL_EXPORT ScopedSetGLToRealGLApi {
  public:
   ScopedSetGLToRealGLApi();
   ~ScopedSetGLToRealGLApi();
 
  private:
   GLApi* old_gl_api_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedSetGLToRealGLApi);
 };
 
-}  // namespace gfx
+}  // namespace gl
 
 #endif  // UI_GL_SCOPED_API_H_