Remove direct access to enqueuer through use of WorldImpact

pkg/compiler/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 dart2js and measure its performance.
 library compiler.tool.perf;
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:compiler/compiler_new.dart';
 import 'package:compiler/src/apiimpl.dart';
 import 'package:compiler/src/compiler.dart';
-import 'package:compiler/src/kernel/task.dart';
 import 'package:compiler/src/elements/elements.dart';
 import 'package:compiler/src/common.dart';
 import 'package:compiler/src/diagnostics/diagnostic_listener.dart';
 import 'package:compiler/src/diagnostics/messages.dart'
     show Message, MessageTemplate;
 import 'package:compiler/src/io/source_file.dart';
 import 'package:compiler/src/options.dart';
 import 'package:compiler/src/parser/element_listener.dart' show ScannerOptions;
 import 'package:compiler/src/parser/listener.dart';
 import 'package:compiler/src/parser/node_listener.dart' show NodeListener;
 import 'package:compiler/src/parser/parser.dart' show Parser;
 import 'package:compiler/src/parser/partial_parser.dart';
 import 'package:compiler/src/platform_configuration.dart' as platform;
 import 'package:compiler/src/scanner/scanner.dart';
 import 'package:compiler/src/source_file_provider.dart';
 import 'package:compiler/src/tokens/token.dart' show Token;
+import 'package:compiler/src/universe/world_impact.dart' show WorldImpact;
 import 'package:package_config/discovery.dart' show findPackages;
 import 'package:package_config/packages.dart' show Packages;
 import 'package:package_config/src/util.dart' show checkValidPackageUri;
 
 /// Cumulative total number of chars scanned.
 int scanTotalChars = 0;
 
 /// Cumulative time spent scanning.
 Stopwatch scanTimer = new Stopwatch();
 
@@ skipping 311 matching lines @@
 
 // We subclass compiler to skip phases and stop after creating kernel.
 class MyCompiler extends CompilerImpl {
   MyCompiler(CompilerInput provider, CompilerDiagnostics handler,
       CompilerOptions options)
       : super(provider, null, handler, options) {}
 
   /// Performs the compilation when all libraries have been loaded.
   void compileLoadedLibraries() =>
       selfTask.measureSubtask("KernelCompiler.compileLoadedLibraries", () {
-        computeMain();
+        WorldImpact mainImpact = computeMain();
         mirrorUsageAnalyzerTask.analyzeUsage(mainApp);
 
         deferredLoadTask.beforeResolution(this);
         impactStrategy = backend.createImpactStrategy(
             supportDeferredLoad: deferredLoadTask.isProgramSplit,
             supportDumpInfo: options.dumpInfo,
             supportSerialization: serialization.supportSerialization);
 
         phase = Compiler.PHASE_RESOLVING;
-
+        enqueuer.resolution.applyImpact(mainImpact);
         // Note: we enqueue everything in the program so we measure generating
         // kernel for the entire code, not just what's reachable from main.
         libraryLoader.libraries.forEach((LibraryElement library) {
           fullyEnqueueLibrary(library, enqueuer.resolution);
         });
 
-        backend.enqueueHelpers(enqueuer.resolution);
+        if (deferredLoadTask.isProgramSplit) {
+          enqueuer.resolution.applyImpact(
+              backend.computeDeferredLoadingImpact());
+        }
+        enqueuer.resolution.applyImpact(backend.computeHelpersImpact());
         resolveLibraryMetadata();
         reporter.log('Resolving...');
         processQueue(enqueuer.resolution, mainFunction);
         enqueuer.resolution.logSummary(reporter.log);
 
         (reporter as CompilerDiagnosticReporter)
             .reportSuppressedMessagesSummary();
 
         if (compilationFailed) {
           // TODO(sigmund): more diagnostics?
           print("compilation failed!");
           exit(1);
         }
 
         closeResolution();
         var program = (backend as dynamic).kernelTask.program;
         print('total libraries: ${program.libraries.length}');
       });
 }