Added IsConstructorCall to gin::Arguments.

Added IsConstructorCall to gin::Arguments.

It simply forwards the flag from v8::FunctionCallbackInfo and allows
the function handler that accept gin::Arguments argument to distinguish
between normal function invocation and call as an object construction.

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284123

[Krzysztof Olczyk, 2014-07-18 12:28:39]

Hi abarth, jochen,

could you take a look at this tiny addition to gin::Arguments?

[jochen (gone - plz use gerrit), 2014-07-18 12:29:47]

On 2014/07/18 12:28:39, Krzysztof Olczyk wrote:
> Hi abarth, jochen,
> 
> could you take a look at this tiny addition to gin::Arguments?

Is it possible to add a test for this?

[Krzysztof Olczyk, 2014-07-18 12:40:39]

On 2014/07/18 12:29:47, jochen wrote:
> On 2014/07/18 12:28:39, Krzysztof Olczyk wrote:
> > Hi abarth, jochen,
> > 
> > could you take a look at this tiny addition to gin::Arguments?
> 
> Is it possible to add a test for this?

Mislead by no arguments_unittests, I haven't added tests originally,
but looks like wrappable_unittest is a good place to add such a test.
Uploaded new CL.

[jochen (gone - plz use gerrit), 2014-07-18 13:07:25]

lgtm

[Krzysztof Olczyk, 2014-07-18 13:09:21]

The CQ bit was checked by kolczyk@opera.com

[commit-bot: I haz the power, 2014-07-18 13:10:20]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/kolczyk@opera.com/401823002/20001

[commit-bot: I haz the power, 2014-07-18 16:46:18]

Change committed as 284123