Update zlib to 1.2.11

net/websockets/websocket_inflater.cc

Index: net/websockets/websocket_inflater.cc
diff --git a/net/websockets/websocket_inflater.cc b/net/websockets/websocket_inflater.cc
index 7767821f462bf7a292ed09664cf925d3a0422cbb..91ed7477bebd38c9908e7770c9ad9a639ae3f02e 100644
--- a/net/websockets/websocket_inflater.cc
+++ b/net/websockets/websocket_inflater.cc
@@ -47,9 +47,19 @@ WebSocketInflater::WebSocketInflater(size_t input_queue_capacity,
 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();