[rust] Adding Rust toolchain to DEPS

A previous CL made a CIPD package of the Android team's Rust
toolchain. This CL adds this CIPD package to DEPS, making the
rust compiler available on Linux hosts. Subsequent CLs will add
suitable gn rules, etc.

This is all experimental and won't yet affect production Chromium
builds.

Change-Id: I5334d56de07c2e9b665670625a04cf6d45c30b24
Bug: 1069271
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3116410
Reviewed-by: Alex Gough <[email protected]>
Commit-Queue: Adrian Taylor <[email protected]>
Cr-Commit-Position: refs/heads/main@{#914908}
diff --git a/DEPS b/DEPS
index 274ed82..3bca067 100644
--- a/DEPS
+++ b/DEPS
@@ -491,6 +491,16 @@
     'dep_type': 'cipd',
     'condition': '(host_os == "linux" or host_os == "win") and checkout_reclient',
   },
+  'src/third_party/android_rust_toolchain/toolchain': {
+    'packages': [
+      {
+        'package': 'chromium/third_party/android_rust_toolchain/linux-amd64',
+        'version': 'u4qRwAAw_08dL-gXhJDVoRziUQp4cfF0m9TQS6f-ylMC',
+      },
+    ],
+    'dep_type': 'cipd',
+    'condition': '(host_os == "linux")',
+  },
 
   'src/android_webview/tools/cts_archive': {
       'packages': [