BP_Attachment::validate_mime_types()

	protected function validate_mime_types() {
		$wp_mimes = get_allowed_mime_types();
		$valid_mimes = array();

		// Set the allowed mimes for the upload.
		foreach ( (array) $this->allowed_mime_types as $ext ) {
			foreach ( $wp_mimes as $ext_pattern => $mime ) {
				if ( $ext !== '' && strpos( $ext_pattern, $ext ) !== false ) {
					$valid_mimes[$ext_pattern] = $mime;
				}
			}
		}
		return $valid_mimes;
	}