Auto merge of #29909 - mrobinson:mach-bootstrap-macos, r=mukilan

Implement `./mach bootstrap` for MacOS

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---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes do not require tests because they just change build scripts.

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4 files changed, 20 insertions, 6 deletions

diff --git a/.github/workflows/mac.yml b/.github/workflows/mac.yml
index 2724f5044de..c169df3693f 100644
--- a/.github/workflows/mac.yml
+++ b/.github/workflows/mac.yml
@@ -57,8 +57,7 @@ jobs:
       - name: Bootstrap
         run: |
           python3 -m pip install --upgrade pip virtualenv
-          python3 ./mach bootstrap-gstreamer
-          brew install gnu-tar
+          python3 ./mach bootstrap
       - name: Release build
         run: |
           python3 ./mach build --release --with-${{ env.LAYOUT }}
diff --git a/README.md b/README.md
index 042065368de..efdf478175a 100644
--- a/README.md
+++ b/README.md
@@ -23,12 +23,11 @@ manually, try the [manual build setup][manual-build].
 ### macOS
 
 - Install [Xcode](https://developer.apple.com/xcode/)
+- Install [Homebrew](https://brew.sh/)
 - Run `curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh`
-- Run `./mach bootstrap-gstreamer`.
-  *This will install the recommended version of GStreamer globally on your system.*
-- Run `brew bundle install --file=etc/homebrew/Brewfile`
 - Run `pip install virtualenv`
-
+- Run `./mach bootstrap`<br/>
+  *Note: This will install the recommended version of GStreamer globally on your system.*
 
 ### Linux
 
diff --git a/etc/homebrew/Brewfile b/etc/homebrew/Brewfile
index 008f8628d59..b9a8874a0a5 100644
--- a/etc/homebrew/Brewfile
+++ b/etc/homebrew/Brewfile
@@ -1,3 +1,4 @@
 # Runtime dependencies
 
 brew "xz"
+brew "gnu-tar"
diff --git a/python/servo/platform/macos.py b/python/servo/platform/macos.py
index 0f5ca632b2f..38169e9a75a 100644
--- a/python/servo/platform/macos.py
+++ b/python/servo/platform/macos.py
@@ -54,6 +54,21 @@ class MacOS(Base):
             return False
         return True
 
+    def _platform_bootstrap(self, _cache_dir: str, force: bool) -> bool:
+        installed_something = False
+        try:
+            brewfile = os.path.join(util.SERVO_ROOT, "etc", "homebrew", "Brewfile")
+            output = subprocess.check_output(
+                ['brew', 'bundle', 'install', "--file", brewfile]
+            ).decode("utf-8")
+            print(output)
+            installed_something = "Installing" in output
+        except subprocess.CalledProcessError as e:
+            print("Could not run homebrew. Is it installed?")
+            raise e
+        installed_something |= self._platform_bootstrap_gstreamer(False)
+        return installed_something
+
     def _platform_bootstrap_gstreamer(self, force: bool) -> bool:
         if not force and self.is_gstreamer_installed(cross_compilation_target=None):
             return False