Address Ivan's comments.

runtime/lib/array.dart

Index: runtime/lib/array.dart
diff --git a/runtime/lib/array.dart b/runtime/lib/array.dart
index 11c9053716b0342906cce59e393ce2cb1904bfee..7d34a823638d9796a16ddbfd18ce2265605ccf76 100644
--- a/runtime/lib/array.dart
+++ b/runtime/lib/array.dart
@@ -61,19 +61,25 @@ class _ObjectArray<E> implements List<E> {
 
   // Collection interface.
 
-  bool contains(E element) => Collections.contains(this, element);
+  bool contains(E element) {
+    return Collections.contains(this, element);
+  }
 
   void forEach(f(E element)) {
     Collections.forEach(this, f);
   }
 
-  Iterable mappedBy(f(E element)) => new MappedIterable<E, dynamic>(this, f);
+  Iterable mappedBy(f(E element)) {
+    return new MappedIterable<E, dynamic>(this, f);
+  }
 
   reduce(initialValue, combine(previousValue, E element)) {
     return Collections.reduce(this, initialValue, combine);
   }
 
-  Iterable<E> where(bool f(E element)) => new WhereIterable<E>(this, f);
+  Iterable<E> where(bool f(E element)) {
+    return new WhereIterable<E>(this, f);
+  }
 
   bool every(bool f(E element)) {
     return Collections.every(this, f);
@@ -100,7 +106,9 @@ class _ObjectArray<E> implements List<E> {
     return Arrays.lastIndexOf(this, element, start);
   }
 
-  Iterator<E> get iterator => new _FixedSizeArrayIterator<E>(this);
+  Iterator<E> get iterator {
+    return new _FixedSizeArrayIterator<E>(this);
+  }
 
   void add(E element) {
     throw new UnsupportedError(
@@ -208,19 +216,25 @@ class _ImmutableArray<E> implements List<E> {
 
   // Collection interface.
 
-  bool contains(E element) => Collections.contains(this, element);
+  bool contains(E element) {
+    return Collections.contains(this, element);
+  }
 
   void forEach(f(E element)) {
     Collections.forEach(this, f);
   }
 
-  Iterable mappedBy(f(E element)) => new MappedIterable<E, dynamic>(this, f);
+  Iterable mappedBy(f(E element)) {
+    return new MappedIterable<E, dynamic>(this, f);
+  }
 
   reduce(initialValue, combine(previousValue, E element)) {
     return Collections.reduce(this, initialValue, combine);
   }
 
-  Iterable<E> where(bool f(E element)) => new WhereIterable<E>(this, f);
+  Iterable<E> where(bool f(E element)) {
+    return new WhereIterable<E>(this, f);
+  }
 
   bool every(bool f(E element)) {
     return Collections.every(this, f);
@@ -252,7 +266,9 @@ class _ImmutableArray<E> implements List<E> {
     return Arrays.lastIndexOf(this, element, start);
   }
 
-  Iterator<E> get iterator => new _FixedSizeArrayIterator<E>(this);
+  Iterator<E> get iterator {
+    return new _FixedSizeArrayIterator<E>(this);
+  }
 
   void add(E element) {
     throw new UnsupportedError(
@@ -325,5 +341,7 @@ class _FixedSizeArrayIterator<E> implements Iterator<E> {
     return false;
   }
 
-  E get current => _current;
+  E get current {
+    return _current;
+  }
 }