Revert of Add command buffer support for GL_EXT_texture_sRGB_decode

gpu/command_buffer/service/gles2_cmd_validation_autogen.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.
 
 // This file is auto-generated from
 // gpu/command_buffer/build_gles2_cmd_buffer.py
 // It's formatted by clang-format using chromium coding style:
 //    clang-format -i -style=chromium filename
 // DO NOT EDIT!
 
@@ skipping 326 matching lines @@
 
 class TextureMinFilterModeValidator {
  public:
   bool IsValid(const GLenum value) const;
 };
 TextureMinFilterModeValidator texture_min_filter_mode;
 
 ValueValidator<GLenum> texture_parameter;
 ValueValidator<GLenum> texture_sized_color_renderable_internal_format;
 ValueValidator<GLenum> texture_sized_texture_filterable_internal_format;
-class TextureSrgbDecodeExtValidator {
- public:
-  bool IsValid(const GLenum value) const;
-};
-TextureSrgbDecodeExtValidator texture_srgb_decode_ext;
-
 ValueValidator<GLenum> texture_stencil_renderable_internal_format;
 class TextureSwizzleValidator {
  public:
   bool IsValid(const GLenum value) const;
 };
 TextureSwizzleValidator texture_swizzle;
 
 ValueValidator<GLenum> texture_target;
 ValueValidator<GLenum> texture_unsized_internal_format;
 class TextureUsageValidator {
@@ skipping 31 matching lines @@
  public:
   bool IsValid(const GLenum value) const;
 };
 VertexAttribITypeValidator vertex_attrib_i_type;
 
 ValueValidator<GLenum> vertex_attrib_type;
 ValueValidator<GLenum> vertex_attribute;
 ValueValidator<GLenum> vertex_pointer;
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_VALIDATION_AUTOGEN_H_