Update zlib to 1.2.11

net/websockets/websocket_inflater.cc

 // Copyright 2013 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.
 
 #include "net/websockets/websocket_inflater.h"
 
 #include <algorithm>
 #include <deque>
 #include <vector>
 
@@ skipping 29 matching lines @@
                                      size_t output_buffer_capacity)
     : input_queue_(input_queue_capacity),
       output_buffer_(output_buffer_capacity) {
   DCHECK_GT(input_queue_capacity, 0u);
   DCHECK_GT(output_buffer_capacity, 0u);
 }
 
 bool WebSocketInflater::Initialize(int window_bits) {
   DCHECK_LE(8, window_bits);
   DCHECK_GE(15, window_bits);
+
+  // Use a negative value to decompress a raw deflate stream. Upgrade
+  // window_bits = 8 (a 256-byte window) to 9 (a 512-byte window) because zlib
+  // is unable to compress using a 256-byte window. Historically, zlib has
+  // silently increased the window size during compression in this case. This
+  // must also be done during decompression to avoid inadvertently attempting
+  // decompression with a window smaller than what zlib actually would have used
+  // during compression. See https://crbug.com/691074.
+  window_bits = -std::max(window_bits, 9);
+
   stream_.reset(new z_stream);
   memset(stream_.get(), 0, sizeof(*stream_));
-  int result = inflateInit2(stream_.get(), -window_bits);
+  int result = inflateInit2(stream_.get(), window_bits);
   if (result != Z_OK) {
     inflateEnd(stream_.get());
     stream_.reset();
     return false;
   }
   return true;
 }
 
 WebSocketInflater::~WebSocketInflater() {
   if (stream_) {
@@ skipping 211 matching lines @@
   size_t num_bytes_to_copy = std::min(size, capacity_ - tail_of_last_buffer_);
   if (!num_bytes_to_copy)
     return 0;
   IOBufferWithSize* buffer = buffers_.back().get();
   memcpy(&buffer->data()[tail_of_last_buffer_], data, num_bytes_to_copy);
   tail_of_last_buffer_ += num_bytes_to_copy;
   return num_bytes_to_copy;
 }
 
 }  // namespace net