Make mappedBy lazy.

sdk/lib/svg/dartium/svg_dartium.dart

Index: sdk/lib/svg/dartium/svg_dartium.dart
diff --git a/sdk/lib/svg/dartium/svg_dartium.dart b/sdk/lib/svg/dartium/svg_dartium.dart
index 35273a65a30d07d7495be9163e3c2ed44aeb2aa9..157ae2612c740ad01b8bc8b589166b654f6b541b 100644
--- a/sdk/lib/svg/dartium/svg_dartium.dart
+++ b/sdk/lib/svg/dartium/svg_dartium.dart
@@ -473,7 +473,7 @@ class SVGAnimatedLengthList extends NativeFieldWrapperClass1 implements List<SVG
 
   void forEach(void f(SVGAnimatedLength element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(SVGAnimatedLength element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(SVGAnimatedLength element)) => new MappedIterable(this, f);
 
   Collection<SVGAnimatedLength> where(bool f(SVGAnimatedLength element)) =>
      _Collections.where(this, <SVGAnimatedLength>[], f);
@@ -600,7 +600,7 @@ class SVGAnimatedNumberList extends NativeFieldWrapperClass1 implements List<SVG
 
   void forEach(void f(SVGAnimatedNumber element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(SVGAnimatedNumber element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(SVGAnimatedNumber element)) => new MappedIterable(this, f);
 
   Collection<SVGAnimatedNumber> where(bool f(SVGAnimatedNumber element)) =>
      _Collections.where(this, <SVGAnimatedNumber>[], f);
@@ -767,7 +767,7 @@ class SVGAnimatedTransformList extends NativeFieldWrapperClass1 implements List<
 
   void forEach(void f(SVGAnimateTransformElement element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(SVGAnimateTransformElement element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(SVGAnimateTransformElement element)) => new MappedIterable(this, f);
 
   Collection<SVGAnimateTransformElement> where(bool f(SVGAnimateTransformElement element)) =>
      _Collections.where(this, <SVGAnimateTransformElement>[], f);
@@ -3826,7 +3826,7 @@ class SVGLengthList extends NativeFieldWrapperClass1 implements List<SVGLength>
 
   void forEach(void f(SVGLength element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(SVGLength element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(SVGLength element)) => new MappedIterable(this, f);
 
   Collection<SVGLength> where(bool f(SVGLength element)) =>
      _Collections.where(this, <SVGLength>[], f);
@@ -4473,7 +4473,7 @@ class SVGNumberList extends NativeFieldWrapperClass1 implements List<SVGNumber>
 
   void forEach(void f(SVGNumber element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(SVGNumber element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(SVGNumber element)) => new MappedIterable(this, f);
 
   Collection<SVGNumber> where(bool f(SVGNumber element)) =>
      _Collections.where(this, <SVGNumber>[], f);
@@ -5540,7 +5540,7 @@ class SVGPathSegList extends NativeFieldWrapperClass1 implements List<SVGPathSeg
 
   void forEach(void f(SVGPathSeg element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(SVGPathSeg element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(SVGPathSeg element)) => new MappedIterable(this, f);
 
   Collection<SVGPathSeg> where(bool f(SVGPathSeg element)) =>
      _Collections.where(this, <SVGPathSeg>[], f);
@@ -6694,7 +6694,7 @@ class SVGStringList extends NativeFieldWrapperClass1 implements List<String> {
 
   void forEach(void f(String element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(String element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(String element)) => new MappedIterable(this, f);
 
   Collection<String> where(bool f(String element)) =>
      _Collections.where(this, <String>[], f);
@@ -7425,7 +7425,7 @@ class SVGTransformList extends NativeFieldWrapperClass1 implements List<SVGTrans
 
   void forEach(void f(SVGTransform element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(SVGTransform element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(SVGTransform element)) => new MappedIterable(this, f);
 
   Collection<SVGTransform> where(bool f(SVGTransform element)) =>
      _Collections.where(this, <SVGTransform>[], f);
@@ -7908,7 +7908,7 @@ class _SVGElementInstanceList extends NativeFieldWrapperClass1 implements List<S
 
   void forEach(void f(SVGElementInstance element)) => _Collections.forEach(this, f);
 
-  Collection mappedBy(f(SVGElementInstance element)) => _Collections.mappedBy(this, [], f);
+  Iterable mappedBy(f(SVGElementInstance element)) => new MappedIterable(this, f);
 
   Collection<SVGElementInstance> where(bool f(SVGElementInstance element)) =>
      _Collections.where(this, <SVGElementInstance>[], f);