findmissing: support chromeos-6.6

BUG=b:308037824
TEST=none

Change-Id: I1d7368d4d51b063d5d612431422d25366fba410c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/5056794
Tested-by: Guenter Roeck <groeck@chromium.org>
Commit-Queue: Tzung-Bi Shih <tzungbi@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
diff --git a/contrib/findmissing/common.py b/contrib/findmissing/common.py
index 395519e..6c2767b 100755
--- a/contrib/findmissing/common.py
+++ b/contrib/findmissing/common.py
@@ -32,8 +32,8 @@
 CHROMIUM_REVIEW_BASEURL = "https://chromium-review.googlesource.com/a"
 
 # Order BRANCHES from oldest to newest
-CHROMEOS_BRANCHES = ["4.19", "5.4", "5.10", "5.15", "6.1"]
-STABLE_BRANCHES = ["4.19", "5.4", "5.10", "5.15", "6.1"]
+CHROMEOS_BRANCHES = ["4.19", "5.4", "5.10", "5.15", "6.1", "6.6"]
+STABLE_BRANCHES = ["4.19", "5.4", "5.10", "5.15", "6.1", "6.6"]
 
 UPSTREAM_START_BRANCH = "v%s" % CHROMEOS_BRANCHES[0]