Install CIPD ninja using DEPS

See chromium/src's CL https://crrev.com/c/3869740 for the context.

Bug: chromium:1340825
Change-Id: Ifbca7ded426e5a1192400aecb4ed17e3ad4441d0
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/277480
Auto-Submit: Junji Watanabe <jwata@google.com>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38250}

DEPS

diff --git a/DEPS b/DEPS
index 47f33fd..2bb817f 100644
--- a/DEPS
+++ b/DEPS
@@ -31,6 +31,10 @@
 
   # reclient CIPD package version
   'reclient_version': 're_client_version:0.78.0.6f1e751-gomaip',
+
+  # ninja CIPD package version
+  # https://chrome-infra-packages.appspot.com/p/infra/3pp/tools/ninja
+  'ninja_version': 'version:2@1.8.2.chromium.3',
 }
 
 deps = {
@@ -105,6 +109,16 @@
   'src/buildtools/third_party/libunwind/trunk':
     'https://chromium.googlesource.com/external/github.com/llvm/llvm-project/libunwind.git@7ff728a9779cdc8e0639c032dc45cc20f7b4af21',
 
+  'src/third_party/ninja': {
+    'packages': [
+      {
+        'package': 'infra/3pp/tools/ninja/${{platform}}',
+        'version': Var('ninja_version'),
+      }
+    ],
+    'dep_type': 'cipd',
+  },
+
   'src/third_party/android_system_sdk': {
       'packages': [
           {