Roll third_party/zlib/ 39b4a6260..dcf1d0f8c (6 commits)

https://chromium.googlesource.com/chromium/src/third_party/zlib.git/+log/39b4a6260702..dcf1d0f8c952

Created with:
  roll-dep third_party/zlib

TBR=rharrison@chromium.org

Change-Id: I4cdad0cbc3ff95d77a3aad31dfc0dd0dbdfdb4f1
Reviewed-on: https://pdfium-review.googlesource.com/40974
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/DEPS b/DEPS
index 52ce2b9..2081537 100644
--- a/DEPS
+++ b/DEPS
@@ -35,7 +35,7 @@
   'trace_event_revision': '211b3ed9d0481b4caddbee1322321b86a483ca1f',
   'v8_revision': '9cf8abb7ce7e3a3152fb71d0e87678e64f7ab0c8',
   'yasm_source_revision': '720b70524a4424b15fc57e82263568c8ba0496ad',
-  'zlib_revision': '39b4a6260702da4c089eca57136abf40a39667e9',
+  'zlib_revision': 'dcf1d0f8c952f76cfceefb4ba61e004f93ad7287',
 }
 
 deps = {