Fixing analyzer error in polymer_expressions.
Fixing analyzer error in polymer_expressions.

Was complaining "The name 'hash' cannot be referenced in the initializer of a variable with the same name", seems like an incorrect error message for this code (though it is arguably less confusing this way).

TBR
BUG=

Review URL: https://codereview.chromium.org//23583021

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@26892 260f80e4-7a28-3924-810f-c04153c831b5

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