Mac: Add dsymutil to DEPS

Needed for ASAN build on Mac.

Bug: angleproject:4149
Change-Id: If2041727ec9bbe40723a991e7455cad12d05ddff
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1926387
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/DEPS b/DEPS
index ada0282..ea3da35 100644
--- a/DEPS
+++ b/DEPS
@@ -219,6 +219,17 @@
     'condition': 'not build_with_chromium',
   },
 
+  'tools/clang/dsymutil': {
+    'packages': [
+      {
+        'package': 'chromium/llvm-build-tools/dsymutil',
+        'version': 'M56jPzDv1620Rnm__jTMYS62Zi8rxHVq7yw0qeBFEgkC',
+      }
+    ],
+    'condition': 'checkout_mac and not build_with_chromium',
+    'dep_type': 'cipd',
+  },
+
   'tools/md_browser': {
     'url': '{chromium_git}/chromium/src/tools/md_browser@0bfd826f8566a99923e64a782908faca72bc457c',
     'condition': 'not build_with_chromium',