Revert of Add command buffer support for GL_EXT_texture_sRGB_decode

gpu/command_buffer/service/gles2_cmd_validation_implementation_autogen.h

Index: gpu/command_buffer/service/gles2_cmd_validation_implementation_autogen.h
diff --git a/gpu/command_buffer/service/gles2_cmd_validation_implementation_autogen.h b/gpu/command_buffer/service/gles2_cmd_validation_implementation_autogen.h
index 280f736988c48f6c84ff92bf73a1a2a634372220..632eaeedfb8df1e74f4d395a7a912f92ce2423e7 100644
--- a/gpu/command_buffer/service/gles2_cmd_validation_implementation_autogen.h
+++ b/gpu/command_buffer/service/gles2_cmd_validation_implementation_autogen.h
@@ -1216,16 +1216,6 @@
         GL_RGB_YCBCR_420V_CHROMIUM,
 };
 
-bool Validators::TextureSrgbDecodeExtValidator::IsValid(
-    const GLenum value) const {
-  switch (value) {
-    case GL_DECODE_EXT:
-    case GL_SKIP_DECODE_EXT:
-      return true;
-  }
-  return false;
-};
-
 static const GLenum
     valid_texture_stencil_renderable_internal_format_table_es3[] = {
         GL_STENCIL_INDEX8, GL_DEPTH24_STENCIL8, GL_DEPTH32F_STENCIL8,