Add formula for chromium depot tools

Formula/depot-tools.rb

@@ -0,0 +1,36 @@
+class DepotTools < Formula
+  desc "Tools for working with Chromium development"
+  homepage "http://dev.chromium.org/developers/how-tos/install-depot-tools"
+  url "https://chromium.googlesource.com/chromium/tools/depot_tools.git", using: :git, revision: "a657331e90e23e289e85a92af49b64829151f403"
+  version "20220120.a657331e9"
+  license "BSD-3-Clause"
+
+#
+# Credit to https://github.com/Homebrew/homebrew/pull/17675/files
+#
+  
+  depends_on "python@3.9"
+  depends_on "repo"
+
+  def install
+    dst = prefix/'tools'
+    dst.mkpath unless dst.directory?
+    mv Dir.glob('*'), dst
+    %w[gclient gn gcl git-cl hammer drover cpplint.py presubmit_support.py
+      trychange.py git-try wtf weekly git-gs zsh-goodies].each do |tool|
+      (bin/tool).write <<~EOS
+        #!/bin/bash
+        TOOL=#{prefix}/tools/#{tool}
+        export DEPOT_TOOLS_UPDATE=0
+        export PATH="$PATH:#{prefix}/tools"
+        exec "$TOOL" "$@"
+      EOS
+    end
+  end
+
+  test do
+    %w[gclient presubmit_support.py trychange.py].each do |tool|
+      system "#{bin}/#{tool} --version"
+    end
+  end
+end