void GLES2DecoderImpl::DoActiveTexture(GLenum texture_unit) {
  GLuint texture_index = texture_unit - GL_TEXTURE0;
  if (texture_index > group_->max_texture_units()) {
    SetGLError(GL_INVALID_ENUM, "glActiveTexture: texture_unit out of range.");
    return;
  }
  active_texture_unit_ = texture_index;
  glActiveTexture(texture_unit);
}

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