We used `self.headers.getheader` which no longer works. We replace it
with `self.headers.get`.
We change the code to write binary data to `self.wfile` because we get
an exception for writing str and/or None.
which encumbers the validation with additional requirements,
specifically makes it difficult to validate a subclass of `dict` because
it expects a constructor that works like dict.__init__()
see https://travis-ci.org/internetarchive/brozzler/jobs/514858838
(unroll "sudo cat /var/log/brozzler-worker.log")
2019-04-02 20:16:01,792 18595 CRITICAL BrozzlingThread:42073 brozzler.worker.BrozzlerWorker.brozzle_site(worker.py:412) unexpected exception
Traceback (most recent call last):
File "/opt/brozzler-ve3/lib/python3.6/site-packages/brozzler/worker.py", line 379, in brozzle_site
enable_youtube_dl=not self._skip_youtube_dl)
File "/opt/brozzler-ve3/lib/python3.6/site-packages/brozzler/worker.py", line 215, in brozzle_page
browser, site, page, on_screenshot, on_request)
File "/opt/brozzler-ve3/lib/python3.6/site-packages/brozzler/worker.py", line 292, in _browse_page
cookie_db=site.get('cookie_db'))
File "/opt/brozzler-ve3/lib/python3.6/site-packages/brozzler/browser.py", line 341, in start
self.websock_url = self.chrome.start(**kwargs)
File "/opt/brozzler-ve3/lib/python3.6/site-packages/brozzler/chrome.py", line 200, in start
return self._websocket_url()
File "/opt/brozzler-ve3/lib/python3.6/site-packages/brozzler/chrome.py", line 247, in _websocket_url
raise e
Exception: chrome process died with status 1
Use `disk_cache_dir` and `disk_cache_size` only on `Chrome.start` and
not on `Chrome.__init__`.
Drop `disk_cache_dir` and `disk_cache_size` class attributes.
Remove `--disable-cache`, its not used any more.
Rename `disk_cache` to `disk_cache_dir` and use only path (str)
argument.
Decouple `--disk-cache-size` from `--disk-cache-dir` so it is possible
to use either or both.
