Prepare for late creation of ResolutionEnqueuer

pkg/compiler/lib/src/js_backend/backend.dart

Index: pkg/compiler/lib/src/js_backend/backend.dart
diff --git a/pkg/compiler/lib/src/js_backend/backend.dart b/pkg/compiler/lib/src/js_backend/backend.dart
index 82710ac16931a27bd78d0ece82d8c887cf671ea5..be709f53ef62a823ed779c33bc2f6ada50247ca2 100644
--- a/pkg/compiler/lib/src/js_backend/backend.dart
+++ b/pkg/compiler/lib/src/js_backend/backend.dart
@@ -29,10 +29,12 @@ import '../elements/resolution_types.dart';
 import '../elements/types.dart';
 import '../enqueue.dart'
     show
+        DirectEnqueuerStrategy,
         Enqueuer,
         EnqueuerListener,
         EnqueueTask,
         ResolutionEnqueuer,
+        ResolutionWorkItemBuilder,
         TreeShakingEnqueuerStrategy;
 import '../io/multi_information.dart' show MultiSourceInformationStrategy;
 import '../io/position_information.dart' show PositionSourceInformationStrategy;
@@ -444,8 +446,6 @@ class JavaScriptBackend {
   MirrorsData mirrorsData;
   CheckedModeHelpers _checkedModeHelpers;
 
-  ResolutionEnqueuerListener _resolutionEnqueuerListener;
-
   native.NativeResolutionEnqueuer _nativeResolutionEnqueuer;
   native.NativeCodegenEnqueuer _nativeCodegenEnqueuer;
 
@@ -551,24 +551,6 @@ class JavaScriptBackend {
     serialization = new JavaScriptBackendSerialization(nativeData);
     _interceptorDataBuilder = new InterceptorDataBuilderImpl(
         nativeClassData, helpers, commonElements, compiler.resolution);
-    _resolutionEnqueuerListener = new ResolutionEnqueuerListener(
-        kernelTask,
-        compiler.options,
-        compiler.elementEnvironment,
-        commonElements,
-        helpers,
-        impacts,
-        nativeClassData,
-        _interceptorDataBuilder,
-        _backendUsageBuilder,
-        _rtiNeedBuilder,
-        mirrorsData,
-        noSuchMethodRegistry,
-        customElementsResolutionAnalysis,
-        lookupMapLibraryAccess,
-        mirrorsAnalysis,
-        typeVariableAnalysis,
-        _nativeResolutionEnqueuer);
   }
 
   /// The [ConstantSystem] used to interpret compile-time constants for this
@@ -647,9 +629,6 @@ class JavaScriptBackend {
 
   CheckedModeHelpers get checkedModeHelpers => _checkedModeHelpers;
 
-  EnqueuerListener get resolutionEnqueuerListener =>
-      _resolutionEnqueuerListener;
-
   /// Returns constant environment for the JavaScript interpretation of the
   /// constants.
   JavaScriptConstantCompiler get constants {
@@ -929,6 +908,38 @@ class JavaScriptBackend {
   bool isComplexNoSuchMethod(FunctionElement element) =>
       noSuchMethodRegistry.isComplex(element);
 
+  ResolutionEnqueuer createResolutionEnqueuer(
+      CompilerTask task, Compiler compiler) {
+    return new ResolutionEnqueuer(
+        task,
+        compiler.options,
+        compiler.reporter,
+        compiler.options.analyzeOnly && compiler.options.analyzeMain
+            ? const DirectEnqueuerStrategy()
+            : const TreeShakingEnqueuerStrategy(),
+        new ResolutionEnqueuerListener(
+            kernelTask,
+            compiler.options,
+            compiler.elementEnvironment,
+            commonElements,
+            helpers,
+            impacts,
+            nativeClassData,
+            _interceptorDataBuilder,
+            _backendUsageBuilder,
+            _rtiNeedBuilder,
+            mirrorsData,
+            noSuchMethodRegistry,
+            customElementsResolutionAnalysis,
+            lookupMapLibraryAccess,
+            mirrorsAnalysis,
+            typeVariableAnalysis,
+            _nativeResolutionEnqueuer),
+        new ElementResolutionWorldBuilder(
+            this, compiler.resolution, const OpenWorldStrategy()),
+        new ResolutionWorkItemBuilder(compiler.resolution));
+  }
+
   /// Creates an [Enqueuer] for code generation specific to this backend.
   CodegenEnqueuer createCodegenEnqueuer(
       CompilerTask task, Compiler compiler, ClosedWorld closedWorld) {