Update engine (#3637)

Turns out there were more clients of the old paragraph API than I expected.
This patch migrates them to the new API.

bin/cache/engine.version

-28fbcc3a38d94281ba2a77426fda0e157a563735
+a25959370a0181c41794e512bbc8983ae8071238

examples/layers/raw/hello_world.dart

@@ -15,8 +15,7 @@ void beginFrame(Duration timeStamp) {
   final ui.ParagraphBuilder paragraphBuilder = new ui.ParagraphBuilder()
     ..addText('Hello, world.');
   final ui.Paragraph paragraph = paragraphBuilder.build(new ui.ParagraphStyle())
-    ..maxWidth = logicalSize.width
-    ..layout();
+    ..layout(new ui.ParagraphConstraints(width: logicalSize.width));
 
   final ui.Rect physicalBounds = ui.Point.origin & (logicalSize * devicePixelRatio);
   final ui.PictureRecorder recorder = new ui.PictureRecorder();

examples/layers/raw/text.dart

@@ -21,7 +21,7 @@ ui.Picture paint(ui.Rect paintBounds) {
 
   // The paint method of Pargraph draws the contents of the paragraph unto the
   // given canvas.
-  canvas.drawParagraph(paragraph, new ui.Offset(paragraph.maxWidth / -2.0, (paragraph.maxWidth / 2.0) - 125));
+  canvas.drawParagraph(paragraph, new ui.Offset(paragraph.width / -2.0, (paragraph.width / 2.0) - 125));
 
   return recorder.endRecording();
 }
@@ -72,11 +72,10 @@ void main() {
   // left, right, or center alignment. Once built, the contents of the paragraph
   // cannot be altered, but sizing and positioning information can be updated.
   paragraph = builder.build(new ui.ParagraphStyle())
-    // Next, we supply a maximum width that the text is permitted to occupy.
-    ..maxWidth = 180.0
-    // ... and we ask the paragraph to the visual position of each its glyphs as
-    // well as its overall size, subject to its sizing constraints.
-    ..layout();
+    // Next, we supply a width that the text is permitted to occupy and we ask
+    // the paragraph to the visual position of each its glyphs as well as its
+    // overall size, subject to its sizing constraints.
+    ..layout(new ui.ParagraphConstraints(width: 180.0));
 
   // Finally, we register our beginFrame callback and kick off the first frame.
   ui.window.onBeginFrame = beginFrame;

packages/flutter/lib/src/rendering/editable_line.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 Paragraph, ParagraphBuilder, ParagraphStyle, TextBox;
+import 'dart:ui' as ui show Paragraph, ParagraphBuilder, ParagraphConstraints, ParagraphStyle, TextBox;
 
 import 'package:flutter/gestures.dart';
 
@@ -157,11 +157,7 @@ class RenderEditableLine extends RenderBox {
       // TODO(abarth): ParagraphBuilder#build's argument should be optional.
       // TODO(abarth): These min/max values should be the default for ui.Paragraph.
       _layoutTemplate = builder.build(new ui.ParagraphStyle())
-        ..minWidth = 0.0
-        ..maxWidth = double.INFINITY
-        ..minHeight = 0.0
-        ..maxHeight = double.INFINITY
-        ..layout();
+        ..layout(new ui.ParagraphConstraints(width: double.INFINITY));
     }
     return _layoutTemplate.height;
   }

packages/flutter/lib/src/rendering/error.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 Paragraph, ParagraphBuilder, ParagraphStyle, TextStyle;
+import 'dart:ui' as ui show Paragraph, ParagraphBuilder, ParagraphConstraints, ParagraphStyle, TextStyle;
 
 import 'box.dart';
 import 'object.dart';
@@ -103,16 +103,17 @@ class RenderErrorBox extends RenderBox {
   void paint(PaintingContext context, Offset offset) {
     try {
       context.canvas.drawRect(offset & size, new Paint() .. color = backgroundColor);
+      double width;
       if (_paragraph != null) {
         // See the comment in the RenderErrorBox constructor. This is not the
         // code you want to be copying and pasting. :-)
         if (parent is RenderBox) {
           RenderBox parentBox = parent;
-          _paragraph.maxWidth = parentBox.size.width;
+          width = parentBox.size.width;
         } else {
-          _paragraph.maxWidth = size.width;
+          width = size.width;
         }
-        _paragraph.layout();
+        _paragraph.layout(new ui.ParagraphConstraints(width: width));
         context.canvas.drawParagraph(_paragraph, offset);
       }
     } catch (e) { }

packages/flutter/test/engine/paragraph_builder_test.dart

@@ -13,12 +13,7 @@ void main() {
     Paragraph paragraph = builder.build(new ParagraphStyle());
     expect(paragraph, isNotNull);
 
-    paragraph.minWidth = 0.0;
-    paragraph.maxWidth = 800.0;
-    paragraph.minHeight = 0.0;
-    paragraph.maxHeight = 600.0;
-
-    paragraph.layout();
+    paragraph.layout(new ParagraphConstraints(width: 800.0));
     expect(paragraph.width, isNonZero);
     expect(paragraph.height, isNonZero);
   });