Update Zlib to version 1.2.8

net/spdy/spdy_session_unittest.cc

 // Copyright (c) 2012 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/spdy/spdy_session.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/base64.h"
@@ skipping 1857 matching lines @@
   spdy_stream->SendRequestHeaders(std::move(headers), NO_MORE_DATA_TO_SEND);
   EXPECT_TRUE(spdy_stream->HasUrlFromHeaders());
 
   // Write request headers & capture resulting histogram update.
   base::HistogramTester histogram_tester;
 
   base::RunLoop().RunUntilIdle();
   // Regression test of compression performance under the request fixture.
   switch (spdy_util_.spdy_version()) {
     case SPDY3:
+#if defined(USE_SYSTEM_ZLIB)
       histogram_tester.ExpectBucketCount(
           "Net.SpdySynStreamCompressionPercentage", 30, 1);
+#else
+            histogram_tester.ExpectBucketCount(
+          "Net.SpdySynStreamCompressionPercentage", 31, 1);
+#endif
       break;
     case HTTP2:
       histogram_tester.ExpectBucketCount(
           "Net.SpdySynStreamCompressionPercentage", 81, 1);
       break;
     default:
       NOTREACHED();
   }
 
   // Read and process EOF.
@@ skipping 3856 matching lines @@
   ssl_info.cert = ImportCertFromFile(GetTestCertsDirectory(),
                                      "spdy_pooling.pem");
   ssl_info.is_issued_by_known_root = true;
   ssl_info.public_key_hashes.push_back(test::GetTestHashValue(primary_pin));
 
   EXPECT_TRUE(SpdySession::CanPool(
       &tss, ssl_info, "www.example.org", "mail.example.org"));
 }
 
 }  // namespace net