Install CIPD ninja using DEPS

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

Bug: chromium:1340825
Change-Id: I7cd5f576b28f10fdbf5aa3a6ccb3a878af46d24e
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/101130
Auto-Submit: Junji Watanabe <jwata@google.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/.gitignore b/.gitignore
index c0df1c2..aeb1e05 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,10 +8,10 @@
 /third_party/android_ndk
 /third_party/catapult
 /third_party/depot_tools
+/third_party/freetype/src
 /third_party/fuchsia-sdk/images
 /third_party/fuchsia-sdk/images-internal
 /third_party/fuchsia-sdk/sdk
-/third_party/freetype/src
 /third_party/googletest/src
 /third_party/icu
 /third_party/instrumented_libraries
@@ -22,6 +22,7 @@
 /third_party/lss
 /third_party/markupsafe
 /third_party/nasm
+/third_party/ninja/ninja*
 /third_party/skia
 /third_party/test_fonts
 /third_party/zlib
diff --git a/DEPS b/DEPS
index 6f14ac7..57ddc06 100644
--- a/DEPS
+++ b/DEPS
@@ -126,6 +126,10 @@
   # and whatever else without interference from each other.
   'nasm_source_revision': 'fc8e0bd892ae133602f5a6f7a9a6840aa1b75989',
   # Three lines of non-changing comments so that
+  # the commit queue can handle CLs rolling Ninja CIPD package version
+  # and whatever else without interference from each other.
+  'ninja_version': 'version:2@1.8.2.chromium.3',
+  # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling partition_allocator
   # and whatever else without interference from each other.
   'partition_allocator_revision': 'cb1f2e8e09f0fdf1ce32ffbd23960f7811a24582',
@@ -314,6 +318,17 @@
     Var('chromium_git') + '/chromium/deps/nasm.git@' +
         Var('nasm_source_revision'),
 
+  'third_party/ninja': {
+    'packages': [
+      {
+        # https://chrome-infra-packages.appspot.com/p/infra/3pp/tools/ninja
+        'package': 'infra/3pp/tools/ninja/${{platform}}',
+        'version': Var('ninja_version'),
+      }
+    ],
+    'dep_type': 'cipd',
+  },
+
   'third_party/skia': {
     'url': Var('skia_git') + '/skia.git@' + Var('skia_revision'),
     'condition': 'checkout_skia',
diff --git a/third_party/ninja/README.pdfium b/third_party/ninja/README.pdfium
new file mode 100644
index 0000000..e79bd45
--- /dev/null
+++ b/third_party/ninja/README.pdfium
@@ -0,0 +1,17 @@
+Name: ninja
+Short Name: ninja
+URL: https://github.com/ninja-build/ninja
+Revision: See the CIPD version in DEPS
+License: Apache License 2.0
+License File: https://github.com/ninja-build/ninja/blob/master/COPYING
+Security Critical: no
+
+Description:
+Ninja is a small build system with a focus on speed, and is used to build
+this project.
+
+The CIPD packages are built using the 3pp pipeline.
+https://chromium.googlesource.com/infra/infra/+/refs/heads/main/3pp/ninja/
+
+Local Modifications:
+None