Create a new browser package for brand support:

sys utils needs to be refactored before we can finish browser
since sys utils will provide mechanisms to find chromium
issue where BROWSER_PATH might now also be firefox
but I suppose that just means you would have to specify firefox
I think brave will work with this

choreographer/_browser/_unix_pipe_chromium_wrapper.py

@@ -0,0 +1,49 @@
+"""
+_unix_pipe_chromium_wrapper.py provides proper fds to chrome.
+
+By running chromium in a new process (this wrapper), we guarantee
+the user hasn't stolen one of our desired file descriptors, which
+the OS gives away first-come-first-serve everytime someone opens a
+file. chromium demands we use 3 and 4.
+"""
+
+import os
+
+# importing modules has side effects, so we do this before imports
+# ruff: noqa: E402
+
+# chromium reads on 3, writes on 4
+os.dup2(0, 3)  # make our stdin their input
+os.dup2(1, 4)  # make our stdout their output
+
+_inheritable = True
+os.set_inheritable(4, _inheritable)
+os.set_inheritable(3, _inheritable)
+
+import signal
+import subprocess
+import sys
+from functools import partial
+
+# we're a wrapper, the cli is everything that came after us
+cli = sys.argv[1:]
+process = subprocess.Popen(cli, pass_fds=(3, 4))  # noqa: S603 untrusted input
+
+
+def kill_proc(process, _sig_num, _frame):
+    process.terminate()
+    process.wait(5)  # 5 seconds to clean up nicely, it's a lot
+    process.kill()
+
+
+kp = partial(kill_proc, process)
+signal.signal(signal.SIGTERM, kp)
+signal.signal(signal.SIGINT, kp)
+
+process.wait()
+
+# not great but it seems that
+# pipe isn't always closed when chrome closes
+# so we pretend to be chrome and send a bye instead
+# also, above depends on async/sync, platform, etc
+print("{bye}")

choreographer/_browser/chromium.py

@@ -0,0 +1,75 @@
+"""chromium.py provides a class proving tools for running chromium browsers."""
+
+import os
+import platform
+import sys
+from pathlib import Path
+
+# TODO(Andrew): move this to its own subpackage comm # noqa: FIX002, TD003
+from choreographer._pipe import Pipe, WebSocket
+
+if platform.system() == "Windows":
+    import msvcrt
+
+
+class Chromium:
+    def __init__(self, pipe):
+        self._comm = pipe
+        # extra information from pipe
+
+    # where do we get user data dir
+    def get_cli(self, temp_dir, **kwargs):
+        gpu_enabled = kwargs.pop("with_gpu", False)
+        headless = kwargs.pop("headless", True)
+        sandbox = kwargs.pop("with_sandbox", False)
+        if kwargs:
+            raise RuntimeError(
+                "Chromium.get_cli() received " f"invalid args: {kwargs.keys()}",
+            )
+        path = None  # TODO(Andrew): not legit # noqa: FIX002,TD003
+        chromium_wrapper_path = Path(__file__).resolve().parent / "chromium_wrapper.py"
+        if platform.system() != "Windows":
+            cli = [
+                sys.executable,
+                chromium_wrapper_path,
+                path,
+            ]
+        else:
+            cli = [
+                path,
+            ]
+
+        cli.extend(
+            [
+                "--disable-breakpad",
+                "--allow-file-access-from-files",
+                "--enable-logging=stderr",
+                f"--user-data-dir={temp_dir}",
+                "--no-first-run",
+                "--enable-unsafe-swiftshader",
+            ],
+        )
+        if not gpu_enabled:
+            cli.append("--disable-gpu")
+        if headless:
+            cli.append("--headless")
+        if not sandbox:
+            cli.append("--no-sandbox")
+
+        if isinstance(self._comm, Pipe):
+            cli.append("--remote-debugging-pipe")
+            if platform.system() == "Windows":
+                _inheritable = True
+                write_handle = msvcrt.get_osfhandle(self._comm.from_choreo_to_external)
+                read_handle = msvcrt.get_osfhandle(self._comm.from_external_to_choreo)
+                os.set_handle_inheritable(write_handle, _inheritable)
+                os.set_handle_inheritable(read_handle, _inheritable)
+                cli += [
+                    f"--remote-debugging-io-pipes={read_handle!s},{write_handle!s}",
+                ]
+        elif isinstance(self._comm, WebSocket):
+            raise NotImplementedError("Websocket style comms are not implemented yet")
+
+
+def get_env():
+    return os.environ().copy()