Improve how we handle packages/ HTML imports. This resolves better any valid

pkg/polymer/example/canonicalization2/pubspec.yaml

Index: pkg/polymer/example/canonicalization2/pubspec.yaml
diff --git a/pkg/polymer/example/canonicalization2/pubspec.yaml b/pkg/polymer/example/canonicalization2/pubspec.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..868710f7e47e1af9a7f0e9e4b1e65c6528999e15
--- /dev/null
+++ b/pkg/polymer/example/canonicalization2/pubspec.yaml
@@ -0,0 +1,6 @@
+name: canonicalization2
+dependencies:
+  polymer:
+    path: ../../

[kustermann, 2014/01/30 01:41:34]

The canonicalization2 package is using polymer and that should be it. 

You should not use any relative paths here. Why can't you just use 'polymer' as
a dependency?

[Siggi Cherem (dart-lang), 2014/01/30 02:25:00]

I'm not sure why? These packages are apps used for testing only and are never
intended to be published.
I guess you mean 'polymer: any'?

We often accumulate several changes before we publish them. I'm using a relative
path to capture more accurately when a test depends on unpublished features.

That being said, I'm not sure how are these version dependencies used by the
bots. Are the bots going to test with pub's hosted version of polymer, or are we
overriding the dependency to use the existing sources from the repo?

In the case of 'canonicalization*', some of these tests will fail if we run them
with the currently published version of polymer (0.9.4). I plan to release 0.9.5
soon afterwards (I just updated this CL to include a version bump on polymer),
but in the meantime we need to run them against the repo sources.

If the bots ignore/override the dependency version, then I can change the
dependency here to say:
  polymer: ">=0.9.5"

[kustermann, 2014/01/31 19:15:09]

It will be an issue once all our bots will use "real" package-roots (currently
we stupidly create symlinks int out/ReleaseIA32/packages ...):

It was requested that we test all our packages/samples with packages from the
repository AND with packages from pub.dartlang.org. We've created infrastructure
for doing this:
- for every test we see if it's inside a package (canonicalization2 in this
case)
- we will then copy that pubspec.yaml into a temporary place and call 'pub get'
to fetch the dependencies (**)
- we will use the packages directory created by 'pub get' as a package-root for
the test (i.e. we pass it to dart2js/vm/...)

(**) When using public packages we don't modify the pubspec.yaml file. When
using the packages in the repository, we use "dependency overrides" for the
packages we have in the repo.

Now you probably see the issue: If you use a relative path to polymer, and we
copy the pubspec.yaml file to another place and call 'pub get', the relative
path is wrong. I'm not sure if we should have relative paths at all, or we
should special case this situation ....

Note that even though the infrastructure is there (./tools/test.py
--use-public-packages / ./tools/test.py --use-repository-packages), it's not
enabled on the bots yet.

For further discussions please get in touch with rico :)

+dev_dependencies:
+  unittest: any