emulate srgb format for generateMipmap

gpu/command_buffer/service/gles2_cmd_srgb_converter.h

 // Copyright (c) 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 GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_SRGB_CONVERTER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_SRGB_CONVERTER_H_
 
 #include <array>
 
 #include "base/containers/hash_tables.h"
@@ skipping 33 matching lines @@
       const gfx::Size& framebuffer_size,
       GLuint src_framebuffer,
       GLenum src_framebuffer_internal_format,
       GLenum src_framebuffer_format,
       GLenum src_framebuffer_type,
       GLuint dst_framebuffer,
       bool decode,
       bool encode,
       bool enable_scissor_test);
 
+  void GenerateMipmap(const gles2::GLES2Decoder* decoder,
+                      Texture* tex,
+                      GLenum target);
+
  private:
   void InitializeSRGBConverterProgram();
   scoped_refptr<const gles2::FeatureInfo> feature_info_;
 
   bool srgb_converter_initialized_ = false;
 
   GLuint srgb_converter_program_ = 0;
 
   std::array<GLuint, 2> srgb_converter_textures_ = {{0, 0}};
   GLuint srgb_decoder_fbo_ = 0;
   GLuint srgb_encoder_fbo_ = 0;
 
   GLuint srgb_converter_vao_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(SRGBConverter);
 };
 
 }  // namespace gles2.
 }  // namespace gpu.
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_SRGB_CONVERTER_H_