Tweak public APIs and use them in patch_sdk, dart2js, and kernel-service

pkg/front_end/tool/perf.dart

 // Copyright (c) 2016, 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.
 
 /// An entrypoint used to run portions of front_end and measure its performance.
 library front_end.tool.perf;
 
 import 'dart:async';
 import 'dart:io' show Directory, File, Platform, exit;
 
@@ skipping 127 matching lines @@
   }
   Program program = await _kernelForProgramViaDartk(entryUri, options);
   dartkTimer.stop();
   var suffix = useSdkSummary ? '_sum' : '';
   report('kernel_gen_e2e${suffix}', dartkTimer.elapsedMicroseconds);
   return program;
 }
 
 _kernelForProgramViaDartk(Uri source, CompilerOptions options) async {
   var loader = await _createLoader(options, entry: source);
-  if (options.compileSdk) {
-    options.additionalLibraries.forEach(loader.loadLibrary);
-  }
+
+  /// CODE REVIEW COMMENT: additionalLibraries was empty
   loader.loadProgram(source, compileSdk: options.compileSdk);
   _reportErrors(loader.errors, options.onError);
   return loader.program;
 }
 
 /// Create a [DartLoader] using the provided [options].
 ///
 /// If [options] contain no configuration to resolve `.packages`, the [entry]
 /// file will be used to search for a `.packages` file.
 Future<DartLoader> _createLoader(CompilerOptions options,
@@ skipping 18 matching lines @@
 }
 
 DartOptions _convertOptions(CompilerOptions options) {
   return new DartOptions(
       strongMode: options.strongMode,
       sdk: _uriToPath(options.sdkRoot),
       // TODO(sigmund): make it possible to use summaries and still compile the
       // sdk sources.
       sdkSummary: options.compileSdk ? null : _uriToPath(options.sdkSummary),
       packagePath: _uriToPath(options.packagesFileUri),
-      customUriMappings: options.uriOverride,
       declaredVariables: options.declaredVariables);
 }
 
 String _uriToPath(Uri uri) {
   if (uri == null) return null;
   if (uri.scheme != 'file') {
     throw new StateError('Only file URIs are supported: $uri');
   }
   return uri.toFilePath();
 }
@@ skipping 235 matching lines @@
 class _Scanner extends Scanner {
   _Scanner(String contents) : super.create(new CharSequenceReader(contents)) {
     preserveComments = false;
   }
 
   @override
   void reportError(errorCode, int offset, List<Object> arguments) {
     // ignore errors.
   }
 }