Fixed interface documentation

runtime/observatory/lib/src/models/objects/source_location.dart

Index: runtime/observatory/lib/src/models/objects/source_location.dart
diff --git a/runtime/observatory/lib/src/models/objects/source_location.dart b/runtime/observatory/lib/src/models/objects/source_location.dart
index 1e1188baba97d1cf620eea3d887ce05a625f3f48..8a03f13eff09cfa501ebb321f8d4738cab814cd5 100644
--- a/runtime/observatory/lib/src/models/objects/source_location.dart
+++ b/runtime/observatory/lib/src/models/objects/source_location.dart
@@ -8,21 +8,21 @@ abstract class Location {
   /// The script containing the source location.
   ScriptRef get script;
 
-  /// The last token of the location if this is a range. [optional]
+  /// [optional] The first token of the location.
   int get tokenPos;
 }
 
 abstract class SourceLocation implements Location {
-  /// The last token of the location if this is a range.
+  /// The first token of the location.
   int get tokenPos;
 
-  /// The last token of the location if this is a range. [optional]
+  /// [optional] The last token of the location if this is a range.
   int get endTokenPos;
 }
 
 abstract class UnresolvedSourceLocation implements Location {
-  // [optional] The uri of the script containing the source location if the
-  // script has yet to be loaded.
+  /// [optional] The uri of the script containing the source location if the
+  /// script has yet to be loaded.
   String get scriptUri;
 
   /// [optional] An approximate line number for the source location. This may