Avoid 'internal_state' macro pollution from zlib.h.

This ends up conflicting with use of 'internal_state' as a member function
name in mojo header files. It creates problems especially with jumbo builds.
Fixing it here rather than just working around it in the jumbo build helps
avoid others from stumbling over this in the future (especially as we start
utilizing mojo more).

Change-Id: I649fd80eb80c57e445b78819e9dc674adbf901bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1709871
Commit-Queue: Darin Fisher <darin@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#679268}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: c56fa983a92c26a87fdf36027cc03a19edd9c157
diff --git a/chromeconf.h b/chromeconf.h
index 3414831..e9aa386 100644
--- a/chromeconf.h
+++ b/chromeconf.h
@@ -158,7 +158,7 @@
 #define voidpc Cr_z_voidpc
 #define voidpf Cr_z_voidpf
 #define gz_header_s Cr_z_gz_header_s
-#define internal_state Cr_z_internal_state
+/* #undef internal_state */
 /* #undef z_off64_t */
 
 /* An exported symbol that isn't handled by Z_PREFIX in zconf.h */
diff --git a/patches/README b/patches/README
index 4cf06b8..b21d309 100644
--- a/patches/README
+++ b/patches/README
@@ -4,6 +4,7 @@
    build.
  - 0001-simd.patch: integrate Intel SIMD optimizations from
    https://github.com/jtkukunas/zlib/
+ - 0002-uninitializedcheck.patch: prevent uninitialized use of state->check
 
 == Procedure to create a patch file ==