Removing Nullable<unsigned long> for PeriodicSyncRegistration::m_minPeriod

Removing Nullable<unsigned long> for PeriodicSyncRegistration::m_minPeriod

As m_minPeriod will get initialized through dictionary member minPeriod
it will have default value 0.

This cl also removes has*() for minPeriod, networkState, powerState and
tag attribute, as all these are dictionary members with default values, has*() will always return true.

BUG=497142
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197171

[Paritosh Kumar, 2015-06-16 11:41:34]

paritosh.in@samsung.com changed reviewers:
+ jkarlin@chromium.org, philipj@opera.com

[Paritosh Kumar, 2015-06-16 11:41:35]

Please have a look.

[jkarlin, 2015-06-16 11:57:56]

lgtm but please update the bug number in the description

[Paritosh Kumar, 2015-06-16 11:59:31]

On 2015/06/16 11:57:56, jkarlin wrote:
> lgtm but please update the bug number in the description

Ohh, Thanks missed 4. Updated.

[Paritosh Kumar, 2015-06-16 12:01:55]

The CQ bit was checked by paritosh.in@samsung.com

[commit-bot: I haz the power, 2015-06-16 12:02:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1189473007/1

[commit-bot: I haz the power, 2015-06-16 13:24:55]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197171