Revert "Remove WorldImpact from caches when no longer needed."

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

 // Copyright (c) 2012, 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.
 
 part of js_backend;
 
 const VERBOSE_OPTIMIZER_HINTS = false;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked = new Set<HInstruction>();
@@ skipping 1584 matching lines @@
         // go through the builder (below) to generate the lazy initializer for
         // the static variable.
         // We also need to register the use of the cyclic-error helper.
         compiler.enqueuer.codegen.registerStaticUse(
             new StaticUse.staticInvoke(
                 helpers.cyclicThrowHelper, CallStructure.ONE_ARG));
       }
     }
 
     generatedCode[element] = functionCompiler.compile(work);
-    WorldImpact worldImpact =
-        impactTransformer.transformCodegenImpact(work.registry.worldImpact);
-    compiler.dumpInfoTask.registerImpact(element, worldImpact);
-    return worldImpact;
+    return impactTransformer.transformCodegenImpact(work.registry.worldImpact);
   }
 
   native.NativeEnqueuer nativeResolutionEnqueuer(Enqueuer world) {
     return new native.NativeResolutionEnqueuer(world, compiler);
   }
 
   native.NativeEnqueuer nativeCodegenEnqueuer(Enqueuer world) {
     return new native.NativeCodegenEnqueuer(world, compiler, emitter);
   }
 
@@ skipping 988 matching lines @@
     "typed_data": "_internal/js_runtime/lib/typed_data_patch.dart",
     "_internal": "_internal/js_runtime/lib/internal_patch.dart"
   };
 
   @override
   Uri resolvePatchUri(String libraryName, Uri platformConfigUri) {
     String patchLocation = _patchLocations[libraryName];
     if (patchLocation == null) return null;
     return platformConfigUri.resolve(patchLocation);
   }
-
-  @override
-  ImpactStrategy createImpactStrategy(
-      {bool supportDeferredLoad: true,
-       bool supportDumpInfo: true}) {
-    return new JavaScriptImpactStrategy(
-        resolution,
-        compiler.dumpInfoTask,
-        supportDeferredLoad: supportDeferredLoad,
-        supportDumpInfo: supportDumpInfo);
-  }
 }
 
 /// Handling of special annotations for tests.
 class Annotations {
   static final Uri PACKAGE_EXPECT =
       new Uri(scheme: 'package', path: 'expect/expect.dart');
 
   final Compiler compiler;
 
   ClassElement expectNoInlineClass;
@@ skipping 448 matching lines @@
   }
 }
 
 /// Records that [constant] is used by the element behind [registry].
 class Dependency {
   final ConstantValue constant;
   final Element annotatedElement;
 
   const Dependency(this.constant, this.annotatedElement);
 }
-
-class JavaScriptImpactStrategy extends ImpactStrategy {
-  final Resolution resolution;
-  final DumpInfoTask dumpInfoTask;
-  final bool supportDeferredLoad;
-  final bool supportDumpInfo;
-
-  JavaScriptImpactStrategy(this.resolution,
-                           this.dumpInfoTask,
-                           {this.supportDeferredLoad,
-                            this.supportDumpInfo});
-
-  @override
-  void visitImpact(Element element,
-                   WorldImpact impact,
-                   WorldImpactVisitor visitor,
-                   ImpactUseCase impactUse) {
-    // TODO(johnniwinther): Compute the application strategy once for each use.
-    if (impactUse == ResolutionEnqueuer.IMPACT_USE) {
-      if (supportDeferredLoad) {
-        impact.apply(visitor);
-      } else {
-        impact.apply(visitor);
-        resolution.uncacheWorldImpact(element);
-      }
-    } else if (impactUse == DeferredLoadTask.IMPACT_USE) {
-      impact.apply(visitor);
-      resolution.uncacheWorldImpact(element);
-    } else if (impactUse == DumpInfoTask.IMPACT_USE) {
-      impact.apply(visitor);
-      dumpInfoTask.unregisterImpact(element);
-    } else {
-      impact.apply(visitor);
-    }
-  }
-}