Introduce "platform configurations" to replace categories and libraries.dart.

pkg/dart2js_incremental/lib/dart2js_incremental.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js_incremental;
 
 import 'dart:async' show
     EventSink,
     Future;
 
@@ skipping 106 matching lines @@
       {Logger logTime,
        Logger logVerbose}) {
     if (logTime == null) {
       logTime = (_) {};
     }
     if (logVerbose == null) {
       logVerbose = (_) {};
     }
     Future mappingInputProvider(Uri uri) {
       Uri updatedFile = updatedFiles[uri];
-      return inputProvider(updatedFile == null ? uri : updatedFile);
+      return inputProvider.readFromUri(updatedFile == null ? uri : updatedFile);
     }
     LibraryUpdater updater = new LibraryUpdater(
         _compiler,
         mappingInputProvider,
         logTime,
         logVerbose,
         _context);
     _context.registerUriWithUpdates(updatedFiles.keys);
     Future<CompilerImpl> future = _reuseCompiler(updater.reuseLibrary);
-    return future.then((Compiler compiler) {
+    return future.then((CompilerImpl compiler) {
       _compiler = compiler;
       if (compiler.compilationFailed) {
         return null;
       } else {
         String update = updater.computeUpdateJs();
         _updates.add(update);
         return update;
       }
     });
   }
 
   String allUpdates() {
     jsAst.Node updates = jsAst.js.escapedString(_updates.join(""));
 
     JavaScriptBackend backend = _compiler.backend;
 
     jsAst.FunctionDeclaration mainRunner = jsAst.js.statement(r"""
 function dartMainRunner(main, args) {
   #helper.patch(#updates + "\n//# sourceURL=initial_patch.js\n");
   return main(args);
 }""", {'updates': updates, 'helper': backend.namer.accessIncrementalHelper});
 
-    jsAst.Printer printer = new jsAst.Printer(_compiler, null);
-    printer.blockOutWithoutBraces(mainRunner);
-    return printer.outBuffer.getText();
+    return jsAst.prettyPrint(mainRunner, _compiler).getText();
   }
 }
 
 class IncrementalCompilationFailed {
   final String reason;
 
   const IncrementalCompilationFailed(this.reason);
 
   String toString() => "Can't incrementally compile program.\n\n$reason";
 }