Add HasChangeListKind and HasFileListKind methods.

Add HasChangeListKind and HasFileListKind methods.

New methods will be used to figure out what is the returned JSON's type in
following CL.

BUG=224870
TEST=Ran unit_tests

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=193642

[hidehiko, 2013-04-11 08:05:43]

Thank you for your review in advance,
- hidehiko

[kinaba, 2013-04-11 08:12:36]

lgtm

[hidehiko, 2013-04-11 08:15:52]

On 2013/04/11 08:12:36, kinaba wrote:
> lgtm

Oops... I thought I built the code and ran tests, but seems I did something
wrong... Fixing...

[hidehiko, 2013-04-11 08:22:33]

On 2013/04/11 08:15:52, hidehiko wrote:
> On 2013/04/11 08:12:36, kinaba wrote:
> > lgtm
> 
> Oops... I thought I built the code and ran tests, but seems I did something
> wrong... Fixing...

Fixed.  I'm really sorry, but would you mind to take another look?

Thanks,
- hidehiko

[kinaba, 2013-04-11 08:28:08]

Oops, should have noticed this while reviewing, sorry.
lgtm (assuming it compiles and passes tests)

[hashimoto, 2013-04-11 08:28:49]

lgtm

[commit-bot: I haz the power, 2013-04-11 08:29:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hidehiko@chromium.org/14160002/4001

[commit-bot: I haz the power, 2013-04-11 09:00:52]

Sorry for I got bad news for ya.
Compile failed with a clobber build on win7_aura.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win7_aura&...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-04-11 12:42:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hidehiko@chromium.org/14160002/4001

[commit-bot: I haz the power, 2013-04-11 14:37:39]

Change committed as 193642