Add brotli decompressor

This commit is for the decoder for brotli compression format.
Brotli is a generic byte-level compression algorithm.

brotli/dec/safe_malloc.h

@@ -0,0 +1,43 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Size-checked memory allocation.
+
+#ifndef BROTLI_UTILS_UTILS_H_
+#define BROTLI_UTILS_UTILS_H_
+
+#include <assert.h>
+
+#include "./types.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+// This is the maximum memory amount that we will ever try to allocate.
+#define BROTLI_MAX_ALLOCABLE_MEMORY (1ULL << 40)
+
+// size-checking safe malloc/calloc: verify that the requested size is not too
+// large, or return NULL. You don't need to call these for constructs like
+// malloc(sizeof(foo)), but only if there's font-dependent size involved
+// somewhere (like: malloc(decoded_size * sizeof(*something))). That's why this
+// safe malloc() borrows the signature from calloc(), pointing at the dangerous
+// underlying multiply involved.
+void* BrotliSafeMalloc(uint64_t nmemb, size_t size);
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}    // extern "C"
+#endif
+
+#endif  /* BROTLI_UTILS_UTILS_H_ */