Reapply 47ecf72 after it was reverted in e431e93e872d9a1c97a5177ebb09d5416f1d659a.

pkg/front_end/lib/src/fasta/kernel/kernel_library_builder.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.
 
 library fasta.kernel_library_builder;
 
 import 'package:front_end/src/fasta/dill/dill_library_builder.dart';
 import 'package:front_end/src/fasta/export.dart';
 import 'package:front_end/src/fasta/import.dart';
 import 'package:kernel/ast.dart';
@@ skipping 484 matching lines @@
         name: name,
         typeVariables: typeVariables,
         modifiers: modifiers,
         interfaces: interfaces,
         charOffset: charOffset);
     checkTypeVariables(typeVariables, supertype.builder);
   }
 
   @override
   void addField(
+      String documentationComment,
       List<MetadataBuilder> metadata,
       int modifiers,
       KernelTypeBuilder type,
       String name,
       int charOffset,
       Token initializerTokenForInference,
       bool hasInitializer) {
     addBuilder(
         name,
-        new KernelFieldBuilder(metadata, type, name, modifiers, this,
-            charOffset, initializerTokenForInference, hasInitializer),
+        new KernelFieldBuilder(
+            documentationComment,
+            metadata,
+            type,
+            name,
+            modifiers,
+            this,
+            charOffset,
+            initializerTokenForInference,
+            hasInitializer),
         charOffset);
   }
 
   String computeAndValidateConstructorName(String name, int charOffset) {
     String className = currentDeclaration.name;
     bool startsWithClassName = name.startsWith(className);
     if (startsWithClassName && name.length == className.length) {
       // Unnamed constructor or factory.
       return "";
     }
     int index = name.indexOf(".");
     if (startsWithClassName && index == className.length) {
       // Named constructor or factory.
       return name.substring(index + 1);
     }
     if (index == -1) {
       // A legal name for a regular method, but not for a constructor.
       return null;
     }
     String suffix = name.substring(index + 1);
     addCompileTimeError(
         templateIllegalMethodName.withArguments(name, "$className.$suffix"),
         charOffset,
         fileUri);
     return suffix;
   }
 
   void addProcedure(
+      String documentationComment,
       List<MetadataBuilder> metadata,
       int modifiers,
       KernelTypeBuilder returnType,
       String name,
       List<TypeVariableBuilder> typeVariables,
       List<FormalParameterBuilder> formals,
       ProcedureKind kind,
       int charOffset,
       int charOpenParenOffset,
       int charEndOffset,
       String nativeMethodName,
       {bool isTopLevel}) {
     // Nested declaration began in `OutlineBuilder.beginMethod` or
     // `OutlineBuilder.beginTopLevelMethod`.
     endNestedDeclaration(name).resolveTypes(typeVariables, this);
     ProcedureBuilder procedure;
     String constructorName =
         isTopLevel ? null : computeAndValidateConstructorName(name, charOffset);
     if (constructorName != null) {
       name = constructorName;
       procedure = new KernelConstructorBuilder(
+          documentationComment,
           metadata,
           modifiers & ~abstractMask,
           returnType,
           name,
           typeVariables,
           formals,
           this,
           charOffset,
           charOpenParenOffset,
           charEndOffset,
           nativeMethodName);
     } else {
       procedure = new KernelProcedureBuilder(
+          documentationComment,
           metadata,
           modifiers,
           returnType,
           name,
           typeVariables,
           formals,
           kind,
           this,
           charOffset,
           charOpenParenOffset,
           charEndOffset,
           nativeMethodName);
     }
     checkTypeVariables(typeVariables, procedure);
     addBuilder(name, procedure, charOffset);
     if (nativeMethodName != null) {
       addNativeMethod(procedure);
     }
   }
 
   void addFactoryMethod(
+      String documentationComment,
       List<MetadataBuilder> metadata,
       int modifiers,
       ConstructorReferenceBuilder constructorNameReference,
       List<FormalParameterBuilder> formals,
       ConstructorReferenceBuilder redirectionTarget,
       int charOffset,
       int charOpenParenOffset,
       int charEndOffset,
       String nativeMethodName) {
     KernelTypeBuilder returnType = addNamedType(
         currentDeclaration.parent.name, <KernelTypeBuilder>[], charOffset);
     // Nested declaration began in `OutlineBuilder.beginFactoryMethod`.
     DeclarationBuilder<KernelTypeBuilder> factoryDeclaration =
         endNestedDeclaration("#factory_method");
     String name = constructorNameReference.name;
     String constructorName =
         computeAndValidateConstructorName(name, charOffset);
     if (constructorName != null) {
       name = constructorName;
     }
     assert(constructorNameReference.suffix == null);
     KernelProcedureBuilder procedure = new KernelProcedureBuilder(
+        documentationComment,
         metadata,
         staticMask | modifiers,
         returnType,
         name,
         <TypeVariableBuilder>[],
         formals,
         ProcedureKind.Factory,
         this,
         charOffset,
         charOpenParenOffset,
@@ skipping 279 matching lines @@
           mixinApplicationClasses.putIfAbsent(name, () => builder);
       if (existing != builder) {
         part.scope.local.remove(name);
       }
     });
     super.includePart(part);
     nativeMethods.addAll(part.nativeMethods);
     boundlessTypeVariables.addAll(part.boundlessTypeVariables);
   }
 }