Make the observatory building be dependent on the pkg_packages target
Make the observatory building be dependent on the pkg_packages target

With the current setup (as of revision 42679), a clean build of:
tools/build.py -mrelease build_observatory

Will throw an error since the args packages has not yet been symlinked into the out/ReleaseIA32/packages location.

R=ager@google.com

Review URL: https://codereview.chromium.org//838173002

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@42683 260f80e4-7a28-3924-810f-c04153c831b5

dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk