38494 Navigator change backup (a: tests, cla: yes, framework, ☸ platform-web)

38495 Roll engine ff49ca1c6e5b..be4c8338a6ab (61 commits) (cla: yes, engine)

38497 handle unexpected exit from frontend server (cla: yes, tool)

38499 Update build web compilers and configure libraries (cla: yes, tool)

38546 Re-land ‘Adding physicalDepth to MediaQueryData & TestWindow’ (a: tests, cla: yes, customer: fuchsia, framework, severe: customer critical)

38558 Fix typos (and a few errors) in the API docs. (cla: yes, framework)

38564 Updating code owners for golden file changes (a: tests, cla: yes, framework, team, will affect goldens)