Issue #1288 - Part 1a: Update brotli to 1.0.7

This also reorganizes the exports in the build system to use `brotli/`
as include directory.

modules/brotli/enc/backward_references.h

@@ -0,0 +1,38 @@
+/* Copyright 2013 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Function to find backward reference copies. */
+
+#ifndef BROTLI_ENC_BACKWARD_REFERENCES_H_
+#define BROTLI_ENC_BACKWARD_REFERENCES_H_
+
+#include "../common/constants.h"
+#include "../common/dictionary.h"
+#include "../common/platform.h"
+#include <brotli/types.h>
+#include "./command.h"
+#include "./hash.h"
+#include "./quality.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+/* "commands" points to the next output command to write to, "*num_commands" is
+   initially the total amount of commands output by previous
+   CreateBackwardReferences calls, and must be incremented by the amount written
+   by this call. */
+BROTLI_INTERNAL void BrotliCreateBackwardReferences(
+    size_t num_bytes, size_t position, const uint8_t* ringbuffer,
+    size_t ringbuffer_mask, const BrotliEncoderParams* params,
+    HasherHandle hasher, int* dist_cache, size_t* last_insert_len,
+    Command* commands, size_t* num_commands, size_t* num_literals);
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif
+
+#endif  /* BROTLI_ENC_BACKWARD_REFERENCES_H_ */