Use tokenPos instead of line/col in the vm service.

runtime/bin/vmservice/client/lib/src/service/object.dart

Index: runtime/bin/vmservice/client/lib/src/service/object.dart
diff --git a/runtime/bin/vmservice/client/lib/src/service/object.dart b/runtime/bin/vmservice/client/lib/src/service/object.dart
index 5e008d16d4e34474c361fd98c440a38b39849955..0341965852e609642a3ae3c9e7986e591fbc63a7 100644
--- a/runtime/bin/vmservice/client/lib/src/service/object.dart
+++ b/runtime/bin/vmservice/client/lib/src/service/object.dart
@@ -819,6 +819,14 @@ class Script extends ServiceObject {
 
   Script._empty(ServiceObjectOwner owner) : super._empty(owner);
 
+  /// This function maps a token position to a line number.
+  int tokenToLine(int token) => _tokenToLine[token];
+  Map _tokenToLine;
+
+  /// This function maps a token position to a column number.
+  int tokenToCol(int token) => _tokenToCol[token];
+  Map _tokenToCol;
+
   void _update(ObservableMap map, bool mapIsRef) {
     kind = map['kind'];
     _url = map['name'];
@@ -826,6 +834,26 @@ class Script extends ServiceObject {
     name = _shortUrl;
     vmName = _url;
     _processSource(map['source']);
+    _parseTokenPosTable(map['tokenPosTable']);
+  }
+
+  void _parseTokenPosTable(List<List<int>> table) {
+    if (table == null) {
+      return;
+    }
+    _tokenToLine = {};
+    _tokenToCol = {};
+    for (var line in table) {
+      // Each entry begins with a line number...
+      var lineNumber = line[0];
+      for (var pos = 1; pos < line.length; pos += 2) {
+        // ...and is followed by (token offset, col number) pairs.
+        var tokenOffset = line[pos];
+        var colNumber = line[pos+1];
+        _tokenToLine[tokenOffset] = lineNumber;
+        _tokenToCol[tokenOffset] = colNumber;
+      }
+    }
   }
 
   void _processHits(List scriptHits) {