Change accessors and AstFactory to use tokens rather than file offsets.

pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart

Index: pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart
index d8fb64f4db7481409c1cedcc03a6c3e19bc1974e..02c9f53be4991a5164c58098b27404fd5a7ceb8e 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart
@@ -2,6 +2,8 @@
 // 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.
 
+import 'package:front_end/src/fasta/scanner/token.dart'
+    show Token, offsetForToken;
 import 'package:kernel/ast.dart';
 
 import '../builder/ast_factory.dart';
@@ -10,8 +12,8 @@ import 'kernel_shadow_ast.dart';
 /// Concrete implementation of [builder.AstFactory] for building a kernel AST.
 class KernelAstFactory implements AstFactory {
   @override
-  KernelBlock block(List<Statement> statements, int charOffset) {
-    return new KernelBlock(statements)..fileOffset = charOffset;
+  KernelBlock block(List<Statement> statements, Token beginToken) {
+    return new KernelBlock(statements)..fileOffset = offsetForToken(beginToken);
   }
 
   @override
@@ -20,38 +22,39 @@ class KernelAstFactory implements AstFactory {
   }
 
   @override
-  KernelIntLiteral intLiteral(value, int charOffset) {
-    return new KernelIntLiteral(value)..fileOffset = charOffset;
+  KernelIntLiteral intLiteral(value, Token token) {
+    return new KernelIntLiteral(value)..fileOffset = offsetForToken(token);
   }
 
   @override
   KernelListLiteral listLiteral(List<Expression> expressions,
-      DartType typeArgument, bool isConst, int charOffset) {
+      DartType typeArgument, bool isConst, Token token) {
     return new KernelListLiteral(expressions,
         typeArgument: typeArgument, isConst: isConst)
-      ..fileOffset = charOffset;
+      ..fileOffset = offsetForToken(token);
   }
 
   @override
-  KernelNullLiteral nullLiteral(int charOffset) {
-    return new KernelNullLiteral()..fileOffset = charOffset;
+  KernelNullLiteral nullLiteral(Token token) {
+    return new KernelNullLiteral()..fileOffset = offsetForToken(token);
   }
 
   @override
-  KernelReturnStatement returnStatement(Expression expression, int charOffset) {
-    return new KernelReturnStatement(expression)..fileOffset = charOffset;
+  KernelReturnStatement returnStatement(Expression expression, Token token) {
+    return new KernelReturnStatement(expression)
+      ..fileOffset = offsetForToken(token);
   }
 
   @override
-  StaticGet staticGet(Member readTarget, int offset) {
-    return new KernelStaticGet(readTarget)..fileOffset = offset;
+  StaticGet staticGet(Member readTarget, Token token) {
+    return new KernelStaticGet(readTarget)..fileOffset = offsetForToken(token);
   }
 
   @override
-  KernelVariableDeclaration variableDeclaration(String name, int charOffset,
+  KernelVariableDeclaration variableDeclaration(String name, Token token,
       {DartType type,
       Expression initializer,
-      int equalsCharOffset = TreeNode.noOffset,
+      Token equalsToken,
       bool isFinal: false,
       bool isConst: false}) {
     return new KernelVariableDeclaration(name,
@@ -59,7 +62,7 @@ class KernelAstFactory implements AstFactory {
         initializer: initializer,
         isFinal: isFinal,
         isConst: isConst)
-      ..fileOffset = charOffset
-      ..fileEqualsOffset = equalsCharOffset;
+      ..fileOffset = offsetForToken(token)
+      ..fileEqualsOffset = offsetForToken(equalsToken);
   }
 }