Fix running 'import run_isolated' at python interactive prompt.

Fix running 'import run_isolated' at python interactive prompt.

This was breaking 'import swarming' since it imports run_isolated.

swarming.py:
- Rename manifest_hash to isolated_hash, the previous name was confusing.
- Only add the data section if necessary, if .zip_and_upload() was called.
- Assumes slave_os is already the proper key in PLATFORM_MAPPING_SWARMING.
- Have polling quit sooner.

R=vadimsh@chromium.org
BUG=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=226272

[Vadim Sh., 2013-10-01 18:59:50]

lgtm with nit

https://codereview.chromium.org/25549003/diff/1/run_isolated.py
File run_isolated.py (right):

https://codereview.chromium.org/25549003/diff/1/run_isolated.py#newcode42
run_isolated.py:42: MAIN_DIR = (
nit: I'd change it into regular 'if' and added comment describing when
get_main_script_path is None:

if zip_package.get_main_script_path():
  ....
else:
  # This happens when running from interactive interpreter shell.
  MAIN_DIR = None

https://codereview.chromium.org/25549003/diff/1/utils/zip_package.py
File utils/zip_package.py (right):

https://codereview.chromium.org/25549003/diff/1/utils/zip_package.py#newcode240
utils/zip_package.py:240: return get_module_zip_archive(main) or getattr(main,
'__file__', None)
oops.. I always forget that getattr needs explicit None for default value.

[M-A Ruel, 2013-10-01 19:06:35]

https://codereview.chromium.org/25549003/diff/1/run_isolated.py
File run_isolated.py (right):

https://codereview.chromium.org/25549003/diff/1/run_isolated.py#newcode42
run_isolated.py:42: MAIN_DIR = (
On 2013/10/01 18:59:51, Vadim Sh. wrote:
> nit: I'd change it into regular 'if' and added comment describing when
> get_main_script_path is None:
> 
> if zip_package.get_main_script_path():
>   ....
> else:
>   # This happens when running from interactive interpreter shell.
>   MAIN_DIR = None

Done.

[commit-bot: I haz the power, 2013-10-01 19:06:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/maruel@chromium.org/25549003/7001

[commit-bot: I haz the power, 2013-10-01 19:08:02]

Change committed as 226272