GSUtils: allow uploads to happen ALWAYS, IF_NEW, or IF_MODIFIED

GSUtils: allow uploads to happen ALWAYS, IF_NEW, or IF_MODIFIED

This will allow us to upload image files most efficiently.

BUG=skia:1942
R=borenet@google.com

Committed: https://skia.googlesource.com/common/+/c0a68c7

[epoger, 2014-07-23 19:52:02]

Eric: PTAL as of patchset 4.

I am proud that this CL adds functionality while removing lines.  All hail
**kwargs.


I suggest reviewing it in two pieces:

1. the diff between orig and patchset 2, in which I replace the only_if_modified
param with upload_if

2. the diff between patchsets 2 and 4, in which I make upload_dir_contents()
call upload_file() using **kwargs so that we don't have to implement all the
args in both places

[borenet, 2014-07-24 14:21:50]

Reviewing diff between patch sets 2 and 4 now.

https://codereview.chromium.org/418503005/diff/20001/py/utils/gs_utils.py
File py/utils/gs_utils.py (right):

https://codereview.chromium.org/418503005/diff/20001/py/utils/gs_utils.py#new...
py/utils/gs_utils.py:222: 
I might add an "elif upload_if != self.UploadIf.ALWAYS: raise" case.

[borenet, 2014-07-24 14:25:18]

2:4 LGTM, but I don't think *args or **kwargs parameters should ever need
documentation.

https://codereview.chromium.org/418503005/diff/60001/py/utils/gs_utils.py
File py/utils/gs_utils.py (right):

https://codereview.chromium.org/418503005/diff/60001/py/utils/gs_utils.py#new...
py/utils/gs_utils.py:251: kwargs: any additional keyword arguments "inherited"
from upload_file()
I'd say you don't need to document kwargs.

[epoger, 2014-07-24 14:49:49]

https://codereview.chromium.org/418503005/diff/20001/py/utils/gs_utils.py
File py/utils/gs_utils.py (right):

https://codereview.chromium.org/418503005/diff/20001/py/utils/gs_utils.py#new...
py/utils/gs_utils.py:222: 
On 2014/07/24 14:21:50, borenet wrote:
> I might add an "elif upload_if != self.UploadIf.ALWAYS: raise" case.

Good idea, thanks! Done.

https://codereview.chromium.org/418503005/diff/60001/py/utils/gs_utils.py
File py/utils/gs_utils.py (right):

https://codereview.chromium.org/418503005/diff/60001/py/utils/gs_utils.py#new...
py/utils/gs_utils.py:251: kwargs: any additional keyword arguments "inherited"
from upload_file()
On 2014/07/24 14:25:18, borenet wrote:
> I'd say you don't need to document kwargs.

From live discussion: this is the best way we could think of to document the
behavior.

[epoger, 2014-07-24 14:50:00]

Committed patchset #5 manually as rc0a68c7 (presubmit successful).