Change scm.GIT.CaptureStatus to ignore unmerged upstream changes.

Change scm.GIT.CaptureStatus to ignore unmerged upstream changes.

With this CL, the patch that is sent to the code review site includes only changes from the nearest common ancestor of the local and the upstream branch. 

A diagram:

     /----B <- local branch
----A-----C <- upstream

Previously, the diff would be simply between C and B, whereas now it's between A and C, even if you update C.

This allows you to continously update origin/trunk without having to rebase/merge your local changes all the time, resulting in the need for less rebuilds.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=43113

[Evan Martin, 2010-03-30 15:32:39]

What program is this for?  Sorry, I have no context.  :)

[Evan Martin, 2010-03-30 15:32:48]

On 2010/03/30 15:32:39, Evan Martin wrote:
> What program is this for?  Sorry, I have no context.  :)

If it's git-try then this LGTM

[Bernhard Bauer, 2010-03-30 16:49:03]

On 2010/03/30 15:32:48, Evan Martin wrote:
> On 2010/03/30 15:32:39, Evan Martin wrote:
> > What program is this for?  Sorry, I have no context.  :)
> 
> If it's git-try then this LGTM

AFAICT, it's used for both git-try and git-cl. I got to this version by
debugging git-cl upload, but I used the patched version for a git try and that
also worked (If it had produced the wrong patch, the the patch phase probably
would have failed).

[Evan Martin, 2010-03-30 16:53:49]

On 2010/03/30 16:49:03, Bernhard Bauer wrote:
> On 2010/03/30 15:32:48, Evan Martin wrote:
> > On 2010/03/30 15:32:39, Evan Martin wrote:
> > > What program is this for?  Sorry, I have no context.  :)
> > 
> > If it's git-try then this LGTM
> 
> AFAICT, it's used for both git-try and git-cl. I got to this version by
> debugging git-cl upload, but I used the patched version for a git try and that
> also worked (If it had produced the wrong patch, the the patch phase probably
> would have failed).

OK, still LGTM then.  :)

[Bernhard Bauer, 2010-04-09 10:20:29]

Heh, turns out it was *not* used in git-try. Another CL coming your way...