Be explicit about use of W version on Windows.
Be explicit about use of W version on Windows.

The trunk builder is unhappy. I don't understand why since we are
defining UNICODE and _UNICODE in our header files. However, let's
just be explicit.

R=sgjesse@google.com,ricow@google.com
BUG=

Review URL: https://codereview.chromium.org//11639017

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@16322 260f80e4-7a28-3924-810f-c04153c831b5

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