Convert analysis starting point to an absolute path before analyzing.
Convert analysis starting point to an absolute path before analyzing.

This ensures that if the analysis starting point is part of an import
loop, then once the analysis engine reaches the starting point again,
it will recognize that it's the same file.

BUG=dartbug.com/21440
R=brianwilkerson@google.com

Review URL: https://codereview.chromium.org//688593005

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@41473 260f80e4-7a28-3924-810f-c04153c831b5

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