Add gcl presubmit script to the dart src tree.

Add gcl presubmit script to the dart src tree.

Currently I just added a tree status check but we can extend this over time.
Committed: https://code.google.com/p/dart/source/detail?r=11575

[Mads Ager (google), 2012-08-29 08:12:56]

LGTM

And this will play nice with the existing PRESUBMIT.py in runtime?

[ricow1, 2012-08-29 08:15:56]

On 2012/08/29 08:12:56, Mads Ager wrote:
> LGTM
> 
> And this will play nice with the existing PRESUBMIT.py in runtime?

Yes, quote from documentation:
When you run gcl upload or gcl commit, gcl will look for all files named
PRESUBMIT.py in folders enclosing the files in your change, up to the repository
root.

For each such file, it will load the file into the Python interpreter and then
call either the CheckChangeOnUpload or CheckChangeOnCommit function depending on
whether you are calling [gcl upload] or [gcl commit].

[Mads Ager (google), 2012-08-29 08:18:06]

On 2012/08/29 08:15:56, ricow1 wrote:
> On 2012/08/29 08:12:56, Mads Ager wrote:
> > LGTM
> > 
> > And this will play nice with the existing PRESUBMIT.py in runtime?
> 
> Yes, quote from documentation:
> When you run gcl upload or gcl commit, gcl will look for all files named
> PRESUBMIT.py in folders enclosing the files in your change, up to the
repository
> root.
> 
> For each such file, it will load the file into the Python interpreter and then
> call either the CheckChangeOnUpload or CheckChangeOnCommit function depending
on
> whether you are calling [gcl upload] or [gcl commit].

Awesome. :)