Add dart:io stubs to ddc sdk, define dart.library.html

pkg/dev_compiler/lib/src/compiler/compiler.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.
 
 import 'dart:collection' show HashSet, Queue;
 import 'dart:convert' show BASE64, JSON, UTF8;
 import 'dart:io' show File;
 import 'package:analyzer/dart/element/element.dart' show LibraryElement;
 import 'package:analyzer/analyzer.dart'
     show AnalysisError, CompilationUnit, ErrorSeverity;
@@ skipping 79 matching lines @@
         resourceProvider: resourceProvider);
 
     var context = createAnalysisContext();
     context.sourceFactory = srcFactory;
     context.typeProvider = sdkResolver.dartSdk.context.typeProvider;
     context.resultProvider =
         new InputPackagesResultProvider(context, summaryData);
     options.declaredVariables.forEach(context.declaredVariables.define);
     context.declaredVariables.define('dart.isVM', 'false');
 
+    // TODO(vsm): Should this be hardcoded?
+    context.declaredVariables.define('dart.library.html', 'true');
+    context.declaredVariables.define('dart.library.io', 'false');

[vsm, 2016/12/14 16:20:28]

FYI - I verified that the tests print "html".  Without this, they print "none"
(and still pass).

+
     return new ModuleCompiler.withContext(context, summaryData);
   }
 
   bool _isFatalError(AnalysisError e, CompilerOptions options) {
     if (errorSeverity(context, e) != ErrorSeverity.ERROR) return false;
 
     // These errors are not fatal in the REPL compile mode as we
     // allow access to private members across library boundaries
     // and those accesses will show up as undefined members unless
     // additional analyzer changes are made to support them.
@@ skipping 444 matching lines @@
     // Fall back to a relative path.
     return path.toUri(path.relative(path.fromUri(uri), from: dir)).toString();
   }
 
   for (int i = 0; i < list.length; i++) {
     list[i] = transformUri(list[i]);
   }
   map['file'] = transformUri(map['file']);
   return map;
 }