Add comment for browser manager.

This CL has no intended behavior change.

Static Lacros configuration should be performed in Lacros rather than
Ash. This is because configuration can cause Lacros P0 blockers, but we
don't want to delay Ash releases for Lacros P0 blockers. The result is
that Lacros can be DOA or have functionality regressions.

Change-Id: Id3df0b8c49059ac1353e8e57044cbf5538f2b710
Bug: 1145713
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518422Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Erik Chen <erikchen@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824223}

chrome/browser/chromeos/crosapi/browser_manager.cc

@@ -310,6 +310,9 @@ void BrowserManager::StartWithLogFile(base::ScopedFD logfd) {
   std::string crash_dir =
       browser_util::GetUserDataDir().Append("crash_dumps").AsUTF8Unsafe();
 
+  // Static configuration should be enabled from Lacros rather than Ash. This
+  // vector should only be used for dynamic configuration.
+  // TODO(https://crbug.com/1145713): Remove existing static configuration.
   std::vector<std::string> argv = {chrome_path,
                                    "--ozone-platform=wayland",
                                    "--user-data-dir=" + user_data_dir,