Update zlib to 1.2.5.
This change applies upstream patches from 1.2.3 to 1.2.5.

BUG=30704,39219
TEST=build and run Chrome without any valgrind errors.

Review URL: http://codereview.chromium.org/8806004

Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: f159d38cb10c746d54e1f380c94878dbeb935b01
34 files changed