Auto merge of #29754 - mrobinson:organize-python-by-platform, r=mukilan

Start organizing platform-specific Python code

This starts to split platform-specific Python code into its own module, which should help to tidy up our mach commands and make things more reusable. This is step one toward fixing #25335.

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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 mach scripts.

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1 files changed, 36 insertions, 0 deletions

diff --git a/python/servo/platform/macos.py b/python/servo/platform/macos.py
new file mode 100644
index 00000000000..6189140cabf
--- /dev/null
+++ b/python/servo/platform/macos.py
@@ -0,0 +1,36 @@
+# Copyright 2023 The Servo Project Developers. See the COPYRIGHT
+# file at the top-level directory of this distribution.
+#
+# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+# option. This file may not be copied, modified, or distributed
+# except according to those terms.
+
+import os
+import subprocess
+
+from .base import Base
+from ..gstreamer import macos_gst_root
+
+
+class MacOS(Base):
+    def __init__(self):
+        pass
+
+    def _platform_is_gstreamer_installed(self) -> bool:
+        # We override homebrew gstreamer if installed and always use pkgconfig
+        # from official gstreamer framework.
+        try:
+            gst_root = macos_gst_root()
+            env = os.environ.copy()
+            env["PATH"] = os.path.join(gst_root, "bin")
+            env["PKG_CONFIG_PATH"] = os.path.join(gst_root, "lib", "pkgconfig")
+            has_gst = subprocess.call(
+                ["pkg-config", "--atleast-version=1.21", "gstreamer-1.0"],
+                stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=env) == 0
+            gst_lib_dir = subprocess.check_output(
+                ["pkg-config", "--variable=libdir", "gstreamer-1.0"], env=env)
+            return has_gst and gst_lib_dir.startswith(bytes(gst_root, 'utf-8'))
+        except FileNotFoundError:
+            return False