Add ImplementedBy attribute for operations merged from [Supplemental=XXX] interfaces.
Add ImplementedBy attribute for operations merged from [Supplemental=XXX] interfaces.

C++ implementations need to know webcore factory name.

R=sra@google.com

Review URL: https://chromiumcodereview.appspot.com//9310119

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@4209 260f80e4-7a28-3924-810f-c04153c831b5

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