LSC Add 'Update Mechanism:' to README.chromium

Bug: 417367156
Change-Id: I318629733d1f75262e030105ec0b684f1307d2fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6646426
Auto-Submit: Jordan Brown <rop@google.com>
Owners-Override: Jordan Brown <rop@google.com>
Commit-Queue: Jordan Brown <rop@google.com>
Commit-Queue: Jiewei Qian <qjw@chromium.org>
Reviewed-by: Jiewei Qian <qjw@chromium.org>
Reviewed-by: Rachael Newitt <renewitt@google.com>
Reviewed-by: Joey Scarr <jsca@google.com>
Cr-Commit-Position: refs/heads/main@{#1475401}
NOKEYCHECK=True
GitOrigin-RevId: da752eb2a3660cf1bf8dac620f6380b89dd953a7

asan/third_party/README.chromium

diff --git a/asan/third_party/README.chromium b/asan/third_party/README.chromium
index 411279f..bfbb67a 100644
--- a/asan/third_party/README.chromium
+++ b/asan/third_party/README.chromium
@@ -3,6 +3,7 @@
 License File: LICENSE.TXT
 Version: a81e45b8bcb8eb274ad73357e10e2cdf8a314a8c
 Revision: a81e45b8bcb8eb274ad73357e10e2cdf8a314a8c
+Update Mechanism: Manual
 URL: https://github.com/llvm/llvm-project/blob/a81e45b8bcb8eb274ad73357e10e2cdf8a314a8c/compiler-rt/lib/asan/scripts/asan_symbolize.py
 Security Critical: no
 Shipped: yes