Rename the global inference task and reduce it's API surface by introducing the

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.
 
 library js_backend.backend;
 
 import 'dart:async' show Future;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
@@ skipping 315 matching lines @@
 
   /// If [true], the compiler will emit code that logs whenever a method is
   /// called. When TRACE_METHOD is 'console' this will be logged
   /// directly in the JavaScript console. When TRACE_METHOD is 'post' the
   /// information will be sent to a server via a POST request.
   static const String TRACE_METHOD = const String.fromEnvironment('traceCalls');
   static const bool TRACE_CALLS =
       TRACE_METHOD == 'post' || TRACE_METHOD == 'console';
   Element traceHelper;
 
-  TypeMask get stringType => compiler.typesTask.stringType;
-  TypeMask get doubleType => compiler.typesTask.doubleType;
-  TypeMask get intType => compiler.typesTask.intType;
-  TypeMask get uint32Type => compiler.typesTask.uint32Type;
-  TypeMask get uint31Type => compiler.typesTask.uint31Type;
-  TypeMask get positiveIntType => compiler.typesTask.positiveIntType;
-  TypeMask get numType => compiler.typesTask.numType;
-  TypeMask get boolType => compiler.typesTask.boolType;
-  TypeMask get dynamicType => compiler.typesTask.dynamicType;
-  TypeMask get nullType => compiler.typesTask.nullType;
+  TypeMask get stringType => compiler.commonMasks.stringType;
+  TypeMask get doubleType => compiler.commonMasks.doubleType;
+  TypeMask get intType => compiler.commonMasks.intType;
+  TypeMask get uint32Type => compiler.commonMasks.uint32Type;
+  TypeMask get uint31Type => compiler.commonMasks.uint31Type;
+  TypeMask get positiveIntType => compiler.commonMasks.positiveIntType;
+  TypeMask get numType => compiler.commonMasks.numType;
+  TypeMask get boolType => compiler.commonMasks.boolType;
+  TypeMask get dynamicType => compiler.commonMasks.dynamicType;
+  TypeMask get nullType => compiler.commonMasks.nullType;
   TypeMask get emptyType => const TypeMask.nonNullEmpty();
+  TypeMask get nonNullType => compiler.commonMasks.nonNullType;
 
   TypeMask _indexablePrimitiveTypeCache;
   TypeMask get indexablePrimitiveType {
     if (_indexablePrimitiveTypeCache == null) {
       _indexablePrimitiveTypeCache =
           new TypeMask.nonNullSubtype(helpers.jsIndexableClass, compiler.world);
     }
     return _indexablePrimitiveTypeCache;
   }
 
@@ skipping 35 matching lines @@
 
   TypeMask _unmodifiableArrayTypeCache;
   TypeMask get unmodifiableArrayType {
     if (_unmodifiableArrayTypeCache == null) {
       _unmodifiableArrayTypeCache = new TypeMask.nonNullExact(
           helpers.jsUnmodifiableArrayClass, compiler.world);
     }
     return _fixedArrayTypeCache;
   }
 
-  TypeMask _nonNullTypeCache;
-  TypeMask get nonNullType {
-    if (_nonNullTypeCache == null) {
-      _nonNullTypeCache = compiler.typesTask.dynamicType.nonNullable();
-    }
-    return _nonNullTypeCache;
-  }
 
   /// Maps special classes to their implementation (JSXxx) class.
   Map<ClassElement, ClassElement> implementationClasses;
 
   bool needToInitializeIsolateAffinityTag = false;
   bool needToInitializeDispatchProperty = false;
 
   final Namer namer;
 
   /**
@@ skipping 200 matching lines @@
         compiler, namer, generateSourceMap, useStartupEmitter);
     typeVariableHandler = new TypeVariableHandler(compiler);
     customElementsAnalysis = new CustomElementsAnalysis(this);
     lookupMapAnalysis = new LookupMapAnalysis(this, reporter);
     jsInteropAnalysis = new JsInteropAnalysis(this);
 
     noSuchMethodRegistry = new NoSuchMethodRegistry(this);
     constantCompilerTask = new JavaScriptConstantTask(compiler);
     impactTransformer = new JavaScriptImpactTransformer(this);
     patchResolverTask = new PatchResolverTask(compiler);
-    functionCompiler = new SsaFunctionCompiler(
-        this, sourceInformationStrategy, useKernel);
+    functionCompiler =
+        new SsaFunctionCompiler(this, sourceInformationStrategy, useKernel);
     serialization = new JavaScriptBackendSerialization(this);
   }
 
   ConstantSystem get constantSystem => constants.constantSystem;
 
   DiagnosticReporter get reporter => compiler.reporter;
 
   CoreClasses get coreClasses => compiler.coreClasses;
 
   CoreTypes get coreTypes => compiler.coreTypes;
@@ skipping 2557 matching lines @@
 
   @override
   void onImpactUsed(ImpactUseCase impactUse) {
     if (impactUse == DeferredLoadTask.IMPACT_USE && !supportSerialization) {
       // TODO(johnniwinther): Allow emptying when serialization has been
       // performed.
       resolution.emptyCache();
     }
   }
 }