Add support for JSON output to checklicenses.py

Add support for JSON output to checklicenses.py

BUG=128664
R=maruel@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=275147

[M-A Ruel, 2014-06-05 15:01:46]

lgtm with two things fixed.

https://codereview.chromium.org/311353002/diff/1/tools/checklicenses/checklic...
File tools/checklicenses/checklicenses.py (right):

https://codereview.chromium.org/311353002/diff/1/tools/checklicenses/checklic...
tools/checklicenses/checklicenses.py:459: with open(options.json, 'w') as f:
'wb'

https://codereview.chromium.org/311353002/diff/1/tools/checklicenses/checklic...
tools/checklicenses/checklicenses.py:484:
PATH_SPECIFIC_WHITELISTED_LICENSES.keys()).difference(used_suppressions)
.keys() is unnecessary, it creates a list when a generator can be used.

[Paweł Hajdan Jr., 2014-06-05 15:38:14]

https://codereview.chromium.org/311353002/diff/1/tools/checklicenses/checklic...
File tools/checklicenses/checklicenses.py (right):

https://codereview.chromium.org/311353002/diff/1/tools/checklicenses/checklic...
tools/checklicenses/checklicenses.py:459: with open(options.json, 'w') as f:
On 2014/06/05 15:01:47, M-A Ruel wrote:
> 'wb'

For now using 'w' for consistency with other json call sites.

https://codereview.chromium.org/311353002/diff/1/tools/checklicenses/checklic...
tools/checklicenses/checklicenses.py:484:
PATH_SPECIFIC_WHITELISTED_LICENSES.keys()).difference(used_suppressions)
On 2014/06/05 15:01:47, M-A Ruel wrote:
> .keys() is unnecessary, it creates a list when a generator can be used.

Done.

[M-A Ruel, 2014-06-05 15:43:29]

lgtm

[Paweł Hajdan Jr., 2014-06-05 16:20:35]

Committed patchset #2 manually as r275147 (presubmit successful).