Fix mangling of zlib API on 64 bit platforms.

It seems https://codereview.chromium.org/8954009/ was a bit
overzealous. On 64 bit platforms, zlib.h attempts to use the 64 bit
API for all callers. But, we were not allowing that, making writing
portable code difficult. This CL updates our manglings in zlib.h so
that on a 64 bit platform the API defaults to the 64 bit version, as
intended.

This change is downstream of https://codereview.chromium.org/13564004/
and must land after it.

R=rsleevi@chromium.org,agl@chromium.org, brettw@chromium.org
BUG=None


Review URL: https://chromiumcodereview.appspot.com/13473020

Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 5a4d2679d2e9b672a99aaa4b59cb638a556f2ead
diff --git a/google.patch b/google.patch
index e2bc2a0..9c3450d 100644
--- a/google.patch
+++ b/google.patch
@@ -207,25 +207,34 @@
  #endif
  
 --- zlib-1.2.5/zlib.h	2010-04-20 12:12:48.000000000 +0800
-+++ zlib/zlib.h	2011-12-16 16:08:48.000000000 +0800
-@@ -1572,12 +1572,14 @@
++++ zlib/zlib.h	2013-04-06 16:08:48.000000000 +0800
+@@ -1572,11 +1572,29 @@
  #endif
  
  #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0
--#  define gzopen gzopen64
--#  define gzseek gzseek64
--#  define gztell gztell64
--#  define gzoffset gzoffset64
--#  define adler32_combine adler32_combine64
--#  define crc32_combine crc32_combine64
-+#  if !defined(MOZZCONF_H)
-+#    define gzopen gzopen64
-+#    define gzseek gzseek64
-+#    define gztell gztell64
-+#    define gzoffset gzoffset64
-+#    define adler32_combine adler32_combine64
-+#    define crc32_combine crc32_combine64
++#  ifdef gzopen
++#    undef gzopen
 +#  endif
+ #  define gzopen gzopen64
++#  ifdef gzseek
++#    undef gzseek
++#  endif
+ #  define gzseek gzseek64
++#  ifdef gztell
++#    undef gztell
++#  endif
+ #  define gztell gztell64
++#  ifdef gzoffset
++#    undef gzoffset
++#  endif
+ #  define gzoffset gzoffset64
++#  ifdef adler32_combine
++#    undef adler32_combine
++#  endif
+ #  define adler32_combine adler32_combine64
++#  ifdef crc32_combine
++#    undef crc32_combine
++#  endif
+ #  define crc32_combine crc32_combine64
  #  ifdef _LARGEFILE64_SOURCE
       ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
-      ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));