Create package for incremental compilation.

dart/pkg/dart2js_incremental/lib/dart2js_incremental.dart

Index: dart/pkg/dart2js_incremental/lib/dart2js_incremental.dart
diff --git a/dart/pkg/dart2js_incremental/lib/dart2js_incremental.dart b/dart/pkg/dart2js_incremental/lib/dart2js_incremental.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6e49c02f4d91695d90f34a2cb1f944135aaad28f
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+++ b/dart/pkg/dart2js_incremental/lib/dart2js_incremental.dart
@@ -0,0 +1,83 @@
+// 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
+    Future;
+
+import 'dart:profiler' show
+    UserTag;
+
+import 'package:compiler/implementation/apiimpl.dart' show
+    Compiler;
+
+import 'package:compiler/compiler.dart' show
+    CompilerInputProvider,
+    CompilerOutputProvider,
+    Diagnostic,
+    DiagnosticHandler;
+
+import 'package:compiler/implementation/dart2jslib.dart' show
+    NullSink;
+
+import 'package:compiler/implementation/js_backend/js_backend.dart' show
+    JavaScriptBackend;
+
+import 'package:compiler/implementation/elements/elements.dart' show
+    LibraryElement;
+
+part 'caching_compiler.dart';
+
+const List<String> INCREMENTAL_OPTIONS = const <String>[
+    '--disable-type-inference',
+    '--incremental-support',
+    '--no-source-maps', // TODO(ahe): Remove this.
+];
+
+class IncrementalCompiler {
+  final Uri libraryRoot;
+  final Uri packageRoot;
+  final CompilerInputProvider inputProvider;
+  final DiagnosticHandler diagnosticHandler;
+  final List<String> options;
+  final CompilerOutputProvider outputProvider;
+  final Map<String, dynamic> environment;
+
+  Compiler _compiler;
+
+  IncrementalCompiler({
+      this.libraryRoot,
+      this.packageRoot,
+      this.inputProvider,
+      this.diagnosticHandler,
+      this.options,
+      this.outputProvider,
+      this.environment}) {
+    if (libraryRoot == null) {
+      throw new ArgumentError('libraryRoot is null.');
+    }
+    if (inputProvider == null) {
+      throw new ArgumentError('inputProvider is null.');
+    }
+    if (diagnosticHandler == null) {
+      throw new ArgumentError('diagnosticHandler is null.');
+    }
+  }
+
+  Future<bool> compile(Uri script) {
+    List<String> options = new List<String>.from(this.options);
+    options.addAll(INCREMENTAL_OPTIONS);
+    _compiler = reuseCompiler(
+        cachedCompiler: _compiler,
+        libraryRoot: libraryRoot,
+        packageRoot: packageRoot,
+        inputProvider: inputProvider,
+        diagnosticHandler: diagnosticHandler,
+        options: options,
+        outputProvider: outputProvider,
+        environment: environment);
+    return _compiler.run(script);
+  }
+}