Change fetch prebuilt pyauto script to download chromedriver.

Change fetch prebuilt pyauto script to download chromedriver.
Also, fix it so it works on linux with a broader range of download sites.
BUG=none
TEST=none

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=98952

[Nirnimesh, 2011-08-26 23:55:27]

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
File pyautolib/fetch_prebuilt_pyauto.py (right):

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
pyautolib/fetch_prebuilt_pyauto.py:77: assert False, 'Could not find chrome zip
at ' + self._url
raise RuntimeError('Could not ...')

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
pyautolib/fetch_prebuilt_pyauto.py:93: """Returns whether a resource exists at
the given URL."""
s/Returns/Determines/

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
pyautolib/fetch_prebuilt_pyauto.py:156: if not self._options.platform == 'win':
You should do this only if it's not set already

[kkania, 2011-08-30 13:30:54]

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
File pyautolib/fetch_prebuilt_pyauto.py (right):

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
pyautolib/fetch_prebuilt_pyauto.py:77: assert False, 'Could not find chrome zip
at ' + self._url
On 2011/08/26 23:55:27, Nirnimesh wrote:
> raise RuntimeError('Could not ...')

Done.  What's the guideline for whether to use assert or raise?  I think last
time I had some exception you told me to use assert instead.

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
pyautolib/fetch_prebuilt_pyauto.py:93: """Returns whether a resource exists at
the given URL."""
On 2011/08/26 23:55:27, Nirnimesh wrote:
> s/Returns/Determines/

Done.

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
pyautolib/fetch_prebuilt_pyauto.py:156: if not self._options.platform == 'win':
Done. What's the reason why we should check first?

[Nirnimesh, 2011-08-30 16:38:34]

LGTM

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
File pyautolib/fetch_prebuilt_pyauto.py (right):

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
pyautolib/fetch_prebuilt_pyauto.py:77: assert False, 'Could not find chrome zip
at ' + self._url
You assert on a conditional. Here it's False, so why pretend to use the
conditional.

I must've asked to use assert in test code instead of raising exception. assert
mixes the conditional and exception in one line; or else you'd require an if
conditional: raise Exception(..), but the if part is redundant in this case

http://codereview.chromium.org/7762010/diff/4001/pyautolib/fetch_prebuilt_pya...
pyautolib/fetch_prebuilt_pyauto.py:156: if not self._options.platform == 'win':
Sorry, I got mixed up with the chat we had about file permissions on
chromedriver archiving. I thought the files were getting copied around, but
they're not -- they're downloaded, so you'll need to set the permissions always.

Feel free to revert it back.