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

ui/gl/gl_enums.h

 // Copyright 2014 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_ENUMS_H_
 #define UI_GL_GL_ENUMS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <string>
 
 #include "ui/gl/gl_export.h"
 
-namespace gfx {
+namespace gl {
 
 class GL_EXPORT GLEnums {
  public:
   struct EnumToString {
     uint32_t value;
     const char* name;
   };
 
   static std::string GetStringEnum(uint32_t value);
   static std::string GetStringBool(uint32_t value);
   static std::string GetStringError(uint32_t value);
 
  private:
   static const EnumToString* const enum_to_string_table_;
   static const size_t enum_to_string_table_len_;
 };
 
-}  // namespace gfx
+}  // namespace gl
 
 #endif  // UI_GL_GL_ENUMS_H_