Split getIntrinsicDimensions into four pieces

sky/sdk/lib/framework/rendering/paragraph.dart

Index: sky/sdk/lib/framework/rendering/paragraph.dart
diff --git a/sky/sdk/lib/framework/rendering/paragraph.dart b/sky/sdk/lib/framework/rendering/paragraph.dart
index 911ad15ed0b9f92ab62aa2b7de950703264313e8..58ad8915d459db8709859e852a9cc37d835bd2d0 100644
--- a/sky/sdk/lib/framework/rendering/paragraph.dart
+++ b/sky/sdk/lib/framework/rendering/paragraph.dart
@@ -40,10 +40,28 @@ class RenderParagraph extends RenderBox {
     }
   }
 
-  Size getIntrinsicDimensions(BoxConstraints constraints) {
+  // We don't currently support this for RenderParagraph
+  double getMinIntrinsicWidth(BoxConstraints constraints) {
     assert(false);
-    return null;
-    // we don't currently support this for RenderParagraph
+    return constraints.constrainWidth(0.0);
+  }
+
+  // We don't currently support this for RenderParagraph
+  double getMaxIntrinsicWidth(BoxConstraints constraints) {
+    assert(false);
+    return constraints.constrainWidth(0.0);
+  }
+
+  // We don't currently support this for RenderParagraph
+  double getMinIntrinsicHeight(BoxConstraints constraints) {
+    assert(false);
+    return constraints.constrainHeight(0.0);
+  }
+
+  // We don't currently support this for RenderParagraph
+  double getMaxIntrinsicHeight(BoxConstraints constraints) {
+    assert(false);
+    return constraints.constrainHeight(0.0);
   }
 
   void performLayout() {