Add BaseTransform.consumePrimary to barback.

Add BaseTransform.consumePrimary to barback.

R=rnystrom@google.com
BUG=16612
Committed: https://code.google.com/p/dart/source/detail?r=33557

[Bob Nystrom, 2014-03-07 21:54:11]

Couple of suggestions but otherwise LGTM. Very nice.

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
File pkg/barback/test/package_graph/group_test.dart (right):

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
pkg/barback/test/package_graph/group_test.dart:204: updateSources(["app|foo.a",
"app|foo.x"]);
Might be cool to expect that foo.a and foo.x are available since only b->c and
b->c consume.

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
File pkg/barback/test/package_graph/transform/pass_through_test.dart (right):

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
pkg/barback/test/package_graph/transform/pass_through_test.dart:273: 
Might be worth making a separate suite for these.

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
pkg/barback/test/package_graph/transform/pass_through_test.dart:326: "consuming
it", () {
It's a subset of this test, but it might be nice to have a standalone test
that's just two siblings consuming the same primary without any conditional
changes.

If nothing else, it makes it easier for a reader to learn the semantics by
working their way up from smaller tests to more complex ones.

[nweiz, 2014-03-11 21:44:05]

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
File pkg/barback/test/package_graph/group_test.dart (right):

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
pkg/barback/test/package_graph/group_test.dart:204: updateSources(["app|foo.a",
"app|foo.x"]);
On 2014/03/07 21:54:11, Bob Nystrom wrote:
> Might be cool to expect that foo.a and foo.x are available since only b->c and
> b->c consume.

Done.

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
File pkg/barback/test/package_graph/transform/pass_through_test.dart (right):

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
pkg/barback/test/package_graph/transform/pass_through_test.dart:273: 
On 2014/03/07 21:54:11, Bob Nystrom wrote:
> Might be worth making a separate suite for these.

Done.

https://codereview.chromium.org/191223004/diff/1/pkg/barback/test/package_gra...
pkg/barback/test/package_graph/transform/pass_through_test.dart:326: "consuming
it", () {
On 2014/03/07 21:54:11, Bob Nystrom wrote:
> It's a subset of this test, but it might be nice to have a standalone test
> that's just two siblings consuming the same primary without any conditional
> changes.
> 
> If nothing else, it makes it easier for a reader to learn the semantics by
> working their way up from smaller tests to more complex ones.

Done.

[nweiz, 2014-03-11 21:44:20]

Committed patchset #2 manually as r33557 (presubmit successful).