Add null check to fill, stroke, clip method

Added null check and exception handling to fill, stroke, clip method.
Added null and invalid argument test cases.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=168280

[Justin Novosad, 2014-02-25 15:36:07]

On 2014/02/25 09:03:42, zino wrote:

Please add a layout test that calls these methods with 'null' as the path
parameter, the test should also call these methods with an argument that is of
the wrong type.

[zino, 2014-02-28 06:38:31]

On 2014/02/25 15:36:07, junov wrote:
> On 2014/02/25 09:03:42, zino wrote:
> 
> Please add a layout test that calls these methods with 'null' as the path
> parameter, the test should also call these methods with an argument that is of
> the wrong type.

Thank you for review.
I uploaded a new patch set.
Could you please review again?

[Justin Novosad, 2014-02-28 15:05:46]

On 2014/02/28 06:38:31, zino wrote:
> On 2014/02/25 15:36:07, junov wrote:
> > On 2014/02/25 09:03:42, zino wrote:
> > 
> > Please add a layout test that calls these methods with 'null' as the path
> > parameter, the test should also call these methods with an argument that is
of
> > the wrong type.
> 
> Thank you for review.
> I uploaded a new patch set.
> Could you please review again?

lgtm

[zino, 2014-03-02 04:52:29]

The CQ bit was checked by jinho.bang@samsung.com

[commit-bot: I haz the power, 2014-03-02 04:52:39]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jinho.bang@samsung.com/179493002/20001

[commit-bot: I haz the power, 2014-03-02 06:23:52]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-02 06:23:54]

Retried try job too often on linux_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_blin...

[zino, 2014-03-03 05:01:13]

The CQ bit was checked by jinho.bang@samsung.com

[commit-bot: I haz the power, 2014-03-03 05:01:25]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jinho.bang@samsung.com/179493002/40001

[commit-bot: I haz the power, 2014-03-03 06:42:34]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-03 06:42:35]

Retried try job too often on linux_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_blin...

[zino, 2014-03-03 07:09:47]

The CQ bit was checked by jinho.bang@samsung.com

[commit-bot: I haz the power, 2014-03-03 07:10:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jinho.bang@samsung.com/179493002/60001

[commit-bot: I haz the power, 2014-03-03 09:02:35]

Change committed as 168280