Restore Syzygy binaries in DEPS.

This is probably what causes failures on the new Win32 ASan bot.
It was removed in https://codereview.webrtc.org/2870883002/
based on the assumption it was no longer needed.

BUG=chromium:677380
TBR=ehmaldonado@webrtc.org

Review-Url: https://codereview.webrtc.org/2872373003 .
Cr-Commit-Position: refs/heads/master@{#18095}

DEPS

diff --git a/DEPS b/DEPS
index db0aeef..6edcdb9 100644
--- a/DEPS
+++ b/DEPS
@@ -493,6 +493,17 @@
                 '-d', 'src/tools/luci-go/linux64',
     ],
   },
+  # Pull the Syzygy binaries, used for optimization and instrumentation.
+  {
+    'name': 'syzygy-binaries',
+    'pattern': '.',
+    'action': ['python',
+               'src/build/get_syzygy_binaries.py',
+               '--output-dir=src/third_party/syzygy/binaries',
+               '--revision=a8456d9248a126881dcfb8707ca7dcdae56e1ac7',
+               '--overwrite',
+    ],
+  },
   {
     # Pull sanitizer-instrumented third-party libraries if requested via
     # GYP_DEFINES.