Implement DeclarationMirror.location for all but ParameterMirrors.

runtime/lib/mirrors_impl.dart

Index: runtime/lib/mirrors_impl.dart
diff --git a/runtime/lib/mirrors_impl.dart b/runtime/lib/mirrors_impl.dart
index acdfaff295936b07068476e83bfb5c8aab2029e3..b8067e418ee1f2557948b54dc2c1bd17e490417f 100644
--- a/runtime/lib/mirrors_impl.dart
+++ b/runtime/lib/mirrors_impl.dart
@@ -80,6 +80,9 @@ String _makeSignatureString(TypeMirror returnType,
   return buf.toString();
 }
 
+SourceLocation _location(reflectee)
+    native "DeclarationMirror_location";
+
 List _metadata(reflectee)
     native 'DeclarationMirror_metadata';
 
@@ -325,9 +328,9 @@ class _SyntheticAccessor implements MethodMirror {
         [new _SyntheticSetterParameter(this, this._target)]);
   }
 
+  SourceLocation get location => null;
   List<InstanceMirror> get metadata => emptyList;
   String get source => null;
-  SourceLocation get location => null;
 }
 
 class _SyntheticSetterParameter implements ParameterMirror {
@@ -349,8 +352,8 @@ class _SyntheticSetterParameter implements ParameterMirror {
   bool get isPrivate => false;
   bool get hasDefaultValue => false;
   InstanceMirror get defaultValue => null;
+  SourceLocation get location => null;
   List<InstanceMirror> get metadata => emptyList;
-  SourceLocation get location => throw new UnimplementedError();
 }
 
 abstract class _LocalObjectMirror extends _LocalMirror implements ObjectMirror {
@@ -637,7 +640,7 @@ class _LocalClassMirror extends _LocalObjectMirror
   final bool isTopLevel = true;
 
   SourceLocation get location {
-    throw new UnimplementedError('ClassMirror.location is not implemented');
+    return _location(_reflectee);
   }
 
   ClassMirror _trueSuperclassField;
@@ -1044,6 +1047,10 @@ abstract class _LocalDeclarationMirror extends _LocalMirror
 
   bool get isPrivate => _n(simpleName).startsWith('_');
 
+  SourceLocation get location {
+    return _location(_reflectee);
+  }
+
   List<InstanceMirror> get metadata {
     // Get the metadata objects, convert them into InstanceMirrors using
     // reflect() and then make them into a Dart list.
@@ -1076,11 +1083,6 @@ class _LocalTypeVariableMirror extends _LocalDeclarationMirror
   bool get isStatic => false;
   bool get isTopLevel => false;
 
-  SourceLocation get location {
-    throw new UnimplementedError(
-        'TypeVariableMirror.location is not implemented');
-  }
-
   TypeMirror _upperBound = null;
   TypeMirror get upperBound {
     if (_upperBound == null) {
@@ -1155,10 +1157,6 @@ class _LocalTypedefMirror extends _LocalDeclarationMirror
     return _owner;
   }
 
-  SourceLocation get location {
-    throw new UnimplementedError('TypedefMirror.location is not implemented');
-  }
-
   TypeMirror _referent = null;
   TypeMirror get referent {
     if (_referent == null) {
@@ -1264,10 +1262,6 @@ class _LocalLibraryMirror extends _LocalObjectMirror implements LibraryMirror {
 
   Type get _instantiator => null;
 
-  SourceLocation get location {
-    throw new UnimplementedError('LibraryMirror.location is not implemented');
-  }
-
   Map<Symbol, DeclarationMirror> _declarations;
   Map<Symbol, DeclarationMirror> get declarations {
     if (_declarations != null) return _declarations;
@@ -1283,6 +1277,10 @@ class _LocalLibraryMirror extends _LocalObjectMirror implements LibraryMirror {
     return _cachedMembers;
   }
 
+  SourceLocation get location {
+    return _location(_reflectee);
+  }
+
   List<InstanceMirror> get metadata {
     // Get the metadata objects, convert them into InstanceMirrors using
     // reflect() and then make them into a Dart list.
@@ -1400,14 +1398,6 @@ class _LocalMethodMirror extends _LocalDeclarationMirror
   bool get isTopLevel => owner is LibraryMirror;
   bool get isSynthetic => false;
 
-  SourceLocation _location;
-  SourceLocation get location {
-    if (_location == null) {
-      _location = _MethodMirror_location(_reflectee);
-    }
-    return _location;
-  }
-
   Type get _instantiator {
     var o = owner;
     while (o is MethodMirror) o = o.owner;
@@ -1490,9 +1480,6 @@ class _LocalMethodMirror extends _LocalDeclarationMirror
 
   static String _MethodMirror_source(reflectee)
       native "MethodMirror_source";
-
-  static SourceLocation _MethodMirror_location(reflectee)
-      native "MethodMirror_location";
 }
 
 class _LocalVariableMirror extends _LocalDeclarationMirror
@@ -1513,10 +1500,6 @@ class _LocalVariableMirror extends _LocalDeclarationMirror
 
   bool get isTopLevel => owner is LibraryMirror;
 
-  SourceLocation get location {
-    throw new UnimplementedError('VariableMirror.location is not implemented');
-  }
-
   Type get _instantiator {
     return owner._instantiator;
   }
@@ -1574,6 +1557,10 @@ class _LocalParameterMirror extends _LocalVariableMirror
 
   bool get hasDefaultValue => _defaultValueReflectee != null;
 
+  SourceLocation get location {
+    throw new UnsupportedError("ParameterMirror.location unimplemented");
+  }
+
   List<InstanceMirror> get metadata {
     if (_unmirroredMetadata == null) return emptyList;
     return new UnmodifiableListView(_unmirroredMetadata.map(reflect));
@@ -1611,6 +1598,7 @@ class _SpecialTypeMirror extends _LocalMirror
 
   DeclarationMirror get owner => null;
 
+  SourceLocation get location => null;
   List<InstanceMirror> get metadata => emptyList;
 
   bool get hasReflectedType => simpleName == #dynamic;
@@ -1625,10 +1613,6 @@ class _SpecialTypeMirror extends _LocalMirror
   bool get isOriginalDeclaration => true;
   TypeMirror get originalDeclaration => this;
 
-  SourceLocation get location {
-    throw new UnimplementedError('TypeMirror.location is not implemented');
-  }
-
   Symbol get qualifiedName => simpleName;
 
   // TODO(11955): Remove once dynamicType and voidType are canonical objects in