Pass locale along to RenderParagraph (#17879)

packages/flutter/lib/src/rendering/paragraph.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui show Gradient, Shader, TextBox;
+import 'dart:ui' as ui show Gradient, Shader, TextBox, Locale;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
@@ -44,6 +44,7 @@ class RenderParagraph extends RenderBox {
     TextOverflow overflow: TextOverflow.clip,
     double textScaleFactor: 1.0,
     int maxLines,
+    ui.Locale locale,
   }) : assert(text != null),
        assert(text.debugAssertIsValid()),
        assert(textAlign != null),
@@ -61,6 +62,7 @@ class RenderParagraph extends RenderBox {
          textScaleFactor: textScaleFactor,
          maxLines: maxLines,
          ellipsis: overflow == TextOverflow.ellipsis ? _kEllipsis : null,
+         locale: locale,
        );
 
   final TextPainter _textPainter;
@@ -174,6 +176,15 @@ class RenderParagraph extends RenderBox {
     markNeedsLayout();
   }
 
+  ui.Locale get locale => _textPainter.locale;
+  set locale(ui.Locale value) {
+    if (_textPainter.locale == value)
+      return;
+    _textPainter.locale = locale;
+    _overflowShader = null;
+    markNeedsLayout();
+  }
+
   void _layoutText({ double minWidth: 0.0, double maxWidth: double.infinity }) {
     final bool widthMatters = softWrap || overflow == TextOverflow.ellipsis;
     _textPainter.layout(minWidth: minWidth, maxWidth: widthMatters ? maxWidth : double.infinity);

packages/flutter/lib/src/widgets/basic.dart

@@ -10,6 +10,7 @@ import 'package:flutter/services.dart';
 
 import 'debug.dart';
 import 'framework.dart';
+import 'localizations.dart';
 
 export 'package:flutter/animation.dart';
 export 'package:flutter/foundation.dart' show
@@ -4341,6 +4342,7 @@ class RichText extends LeafRenderObjectWidget {
       overflow: overflow,
       textScaleFactor: textScaleFactor,
       maxLines: maxLines,
+      locale: Localizations.localeOf(context, nullOk: true),
     );
   }
 
@@ -4354,7 +4356,8 @@ class RichText extends LeafRenderObjectWidget {
       ..softWrap = softWrap
       ..overflow = overflow
       ..textScaleFactor = textScaleFactor
-      ..maxLines = maxLines;
+      ..maxLines = maxLines
+      ..locale = Localizations.localeOf(context, nullOk: true);
   }
 
   @override