Add methods to Collection.

runtime/lib/growable_array.dart

Index: runtime/lib/growable_array.dart
diff --git a/runtime/lib/growable_array.dart b/runtime/lib/growable_array.dart
index 3466ec0fc2fc6455c1e33d4fc73fce07885443f6..6498f20dd8282d36701ea0eb4a15da5fb191b713 100644
--- a/runtime/lib/growable_array.dart
+++ b/runtime/lib/growable_array.dart
@@ -21,6 +21,21 @@ class _GrowableObjectArray<T> implements List<T> {
     return result;
   }
 
+  void remove(Object element) {
+    for (int i = 0; i < this.length; i++) {
+      if (this[i] == element) {
+        int newLength = this.length - 1;
+        Arrays.copy(this,
+                    index + 1,
+                    this,
+                    index,
+                    newLength - index);
+        this.length = newLength;
+        return;
+      }
+    }
+  }
+
   void setRange(int start, int length, List<T> from, [int startFrom = 0]) {
     if (length < 0) {
       throw new ArgumentError("negative length $length");