Add custom field converter to JSONValueConverter.

Add custom field converter to JSONValueConverter.

In the real JSON results, sometimes string value does not literally
mean a string, but labels (enum), URLs, or timestamps.  Custom
field accepts those string values and converting functions for
such fields.

See http://codereview.chromium.org/9147060 for the real use cases.

BUG=109375
TEST=passed

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=117580

[Evan Martin, 2012-01-11 17:20:09]

LGTM

[awong, 2012-01-11 17:32:13]

http://codereview.chromium.org/9184002/diff/1/base/json/json_value_converter.h
File base/json/json_value_converter.h (right):

http://codereview.chromium.org/9184002/diff/1/base/json/json_value_converter....
base/json/json_value_converter.h:69: // RegisterRepeatedMessage for nested
repeated fields.
Can we add some documentation in here to explain how CustomFieldConverter should
be used?

[Jun Mukai, 2012-01-12 07:17:18]

http://codereview.chromium.org/9184002/diff/1/base/json/json_value_converter.h
File base/json/json_value_converter.h (right):

http://codereview.chromium.org/9184002/diff/1/base/json/json_value_converter....
base/json/json_value_converter.h:69: // RegisterRepeatedMessage for nested
repeated fields.
On 2012/01/11 17:32:13, awong wrote:
> Can we add some documentation in here to explain how CustomFieldConverter
should
> be used?

Done.

[awong, 2012-01-12 18:40:48]

LGTM

[commit-bot: I haz the power, 2012-01-13 00:11:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mukai@chromium.org/9184002/6003

[commit-bot: I haz the power, 2012-01-13 02:18:05]

Change committed as 117580